Math Is Fun Forum

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 46,339

Re: 10 second questions

Hi bobbym,

The solutions to 2235 and 2236 are perfect. Very good!

#2237. Show that the straight lines x-2y=0 and 2x+y+1=0 are perpendicular to each other.

#2238. Is the straight line x=2y parallel to 2x-4y+7=0?

#2239. Find the equation of the straight line whose intercepts on the axes are given by 1/3 and 2/5 respectively.

---

It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: 10 second questions

Hi ganesh;

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 46,339

Re: 10 second questions

Hi bobbym,

The solutions to 2237, 2238, and 2239 are perfect. Outstanding!

#2240. Solve: x+y=3, 2x+3y=8.

#2241. Solve: 2x-y=7, 3x-2y=11.

---

It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: 10 second questions

Hi ganesh;

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

santhosh

Member

Registered: 2010-07-19

Posts: 14

Re: 10 second questions

hi ganesh
pls send me proof for the
show that  1=2

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: 10 second questions

Hi santhosh;

Here is where this was discussed, you will find what you are looking  for here:

http://www.mathisfunforum.com/viewtopic … 80#p110680

But remember those are false proofs, 1 ≠ 2

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 46,339

Re: 10 second questions

Hi santhosh

As bobbym referred in post #1567, 1=2 is an aberration.

Hi bobbym,

The replies to 2240 and 2241 are perfect. Well done!

#2242. Find the point of intersection of the straight lines 2x-2y=6 and x+y=3.

#2243. Where does the straight line 6x-3y-30=0 meet (i) x-axis  (ii) y-axis?

---

It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: 10 second questions

Hi ganesh;

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 46,339

Re: 10 second questions

Hi bobbym,

The solutions are correct. Brilliant!

#2244. Find the 17[sup]th[/sup] term of the Geometric Progression 3,6,12,........

#2245. The area of the base of a cylinder is 66 sq.cm.Its height is 20 cm. Find its volume.

#2246. Determine the nature of the roots of the equation x[sup]2[/sup]-11x-30=0.

---

It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: 10 second questions

Hi ganesh;

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 46,339

Re: 10 second questions

Hi bobbym,

The solutions 2244, 2245, and 2246 are perfect. Marvelous!

#2247. A cylinder has radius 7 cm and height 10 cm. Find
(i) volume (ii) curved surface area (iii) total surface area of the cylinder.

#2248. The circumference of the base of a cylinder is 25.45 cm and its height is 15 cm. Find the curved surface area.

#2249. If 3 coins are tossed, then what is the chance of getting exactly one head?

#2250. The sixth and the tenth terms of a Geometric Progression are 63 and 5103 respectively. Find the GP.

---

It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: 10 second questions

Hi ganesh;

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 46,339

Re: 10 second questions

Hi bobbym,

The solutions 2247, 2248, 2249, and 2250 are perfectly correct! Outstanding!

#2251. Find the radius of the cylinder if the area of its curved surface is 352 sq.cm. and its height 16 cm.

#2252. The volume of a cylinder is 448 pi cu.cm. and height 7 cm.Find its curved surface area.

#2253. The radii of two cylinders are in the ratio of 2:3, find the ratio of their volumes if their heights are in the ratio of 5:3.

---

It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: 10 second questions

Hi ganesh;

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 46,339

Re: 10 second questions

Hi bobbym ,
The solutions from 2251, 2252, and 2253 are perfectly right! Well done!

#2254. A rectangle sheet of metal 44 cm long and 20 cm broad is rolled along its length into a cylinder. Find the curved surface area of the cylinder.

#2255. The radius and height of a cylinder are in the ratio 2:7. If the curved surface area of the cylinder is 352 sq.cm., find its radius.

#2256. Through a cylindrical tunnel of diameter 21 meters water flows uniformly at the rate of 18 km per hour. How much water will flow through it in 20 minutes?

---

It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: 10 second questions

Hi ganesh;

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 46,339

Re: 10 second questions

Hi bobbym,

The solutions 2254 and 2255 are perfectly okay. Good work!

---

It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: 10 second questions

Hi ganesh;

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 46,339

Re: 10 second questions

Hi bobbym,

#2256. Find the sum of all numbers between 200 and 400 divisible by 7.

#2257. Find the sum of 12[sup]3[/sup] + 13[sup]3[/sup] + .......... 23[sup]3[/sup].

#2258. A toy is in the form of a cone mounted on a hemisphere. Radius and slant height of the cone are 2.1 cm and 10 cm respectively. Find its surface area.

#2259. A cylinder of radius 3.5 cm and height 12 cm is melted and made into some cones of radius 7 cm and height 3 cm. How many cones can be made?

---

It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: 10 second questions

Hi ganesh;

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 46,339

Re: 10 second questions

Hi bobbym,

The replies to 2256, 2257, and 2259 are correct. Excellent!

#2260. A cone is of radius 7 cm and its slant height is 25 cm. Find the curved surface area of the cone.

#2261. Solve : x[sup]2[/sup] - x - 13 = 0.

---

It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: 10 second questions

Hi ganesh;

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 46,339

Re: 10 second questions

Hi bobbym,

#2262. A watch, which gains 5 seconds in every 3 minutes,  is set right at 6 am. What is the true time in the afternoon of the same day when the watch indicates quarter past three?

#2263. A train traveling at 20 kmph leaves Mumbai at 7.15 am and another traveling at 40 kmph starts at 11.15 am in the same direction. How many km from Mumbai do they meet?

---

It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: 10 second questions

Ho ganesh;

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 46,339

Re: 10 second questions

Hi bobbym,

The solutions I got the same of 2262 and 2263 as you got. Remarkable!

---

It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.