Math Is Fun Forum

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Oral puzzles

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.

anonimnystefy

Real Member

From: Harlan's World

Registered: 2011-05-23

Posts: 16,049

Re: Oral puzzles

hi ganesh

---

“Here lies the reader who will never open this book. He is forever dead.
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 46,276

Re: Oral puzzles

Hi bobbym and anonimnystefy,

The solution #1203 is perfect. Neat job!

#1204. A courtyard 25 meter long and 16 meter broad is to be paved with bricks of dimensions 20 cm by 10 cm. Find the total number of bricks required.

---

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: Oral puzzles

Hi;

---

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: 46,276

Re: Oral puzzles

Hi bobbym,

The solution #1204 is correct. Well done!

#1205. If a man rows at the rate of 5 km/hour in still water and his rate against the current is 3.5 km/hour, then what is man's rate along the current?

---

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: Oral puzzles

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: 46,276

Re: Oral puzzles

Hi bobbym,

The solution #1205 is correct. Good work!

#1206. A man can row 7.5 km/hour in still water. If in a river running at 1.5 km/hour, it takes him 50 minutes to row to a place and back, how far off is the place?

---

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.

anonimnystefy

Real Member

From: Harlan's World

Registered: 2011-05-23

Posts: 16,049

Re: Oral puzzles

hi ganesh

---

“Here lies the reader who will never open this book. He is forever dead.
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Oral puzzles

Hi;

---

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: 46,276

Re: Oral puzzles

Hi anonimnystefy and bobbym,

The solution #1206 is correct. Well done!

#1207. In a stream running at 2 km/hour, a motorboat goes 6 km upstream and back again to the starting point in 33 minutes. Find the speed of the motorboat in still water.

---

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: Oral puzzles

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: 46,276

Re: Oral puzzles

Hi bobbym,

The solution #1207 is correct. Neat job!

#1208. What is the difference between the compound interests on $5,000 for 1½ years at 4% per annum compounded yearly and half-yearly?

---

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: Oral puzzles

Hi;

---

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.

ShivamS

Member

Registered: 2011-02-07

Posts: 3,648

Re: Oral puzzles

#1203
4m
#1204
20000
#1205
6.5 km/h
#1206
3km
#1207
22km/h

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Oral puzzles

Hi Shivamcoder3013;

You can use the hide tags to cover your work.

---

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: 46,276

Re: Oral puzzles

Hi bobbym and Shivamcoder3013,

Shivamcoder3013 : The solutions #1203, #1204, #1205, #1206, and #1207 are correct. Excellent!
(Please use the hide tags when you post the solutions.

 [ hide]Solution to be hidden [ /hide]

.)

bobbym :

# 1209. The compound interest on $30,000 at 7% per annum is $4347.  Find the period in years.

---

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: Oral puzzles

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: 46,276

Re: Oral puzzles

Hi bobbym,

I have edited the solution #1208. Now, the solution in the formula is perfect. This is for your reference.

The solution #1209 is perfect. Excellent!

#1210. If the simple interest on a sum of money for 2 years at 5% per annum is $50, what is the compound interest on the same sum at the same rate (compounded annually) for the same time?

---

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: Oral puzzles

Hi ganesh;

Thanks for the formula.

---

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: 46,276

Re: Oral puzzles

Hi bobbym,

The solution #1210 is correct. Brilliant!

#1211. Given

, find the value of

.

---

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: Oral puzzles

Hi;

---

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.

ShivamS

Member

Registered: 2011-02-07

Posts: 3,648

Re: Oral puzzles

#1208

Last edited by Shivamcoder3013 (2011-09-02 12:09:21)

ShivamS

Member

Registered: 2011-02-07

Posts: 3,648

Re: Oral puzzles

I mean #1209

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 46,276

Re: Oral puzzles

Hi bobbym and Shivamcoder3013,

bobbym : The solution #1211 is correct. Well done!

Shivamcoder3013 : #1208 is correct. Well done!
Regarding solution #1210, see the post number 1291.

#1212. The cost of carpeting a room 18 meter long with a carpet 75 cm wide at $4.50 per meter is $821. Find the breadth of the room.

---

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: Oral puzzles

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.