Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 26,112

Hi,

The solution #3865 is correct. Neat work, Monox D. I-Fly!

#3866. If diameter of a circle is increased by 40%, then by what percent does its area increase?

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

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

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 26,112

Hi,

#3867. If the area of a sector of a circle is 7/20 of the area of the circle, then find the sector angle.

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

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

Offline

**Monox D. I-Fly****Member**- From: Indonesia
- Registered: 2015-12-02
- Posts: 1,269

Actually I never watch Star Wars and not interested in it anyway, but I choose a Yoda card as my avatar in honor of our great friend bobbym who has passed away. May his adventurous soul rest in peace at heaven.

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 26,112

Hi,

The solution #3867 is correct. Excellent, Monox D. I-Fly!

#3868. If the area of a sector of a circle bounded by an arc of of length

cm is equal to square centimeters, then find the radius of the circle.It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

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

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 26,112

Hi,

#3869. The hour hand of a clock is 6 centimeters long. Find the area swept by it between 11.20 am and 11.55 am.

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

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 26,112

Hi,

#3870. The radius of a wheel is 0.25 meter. Find the number of revolutions it will make to travel a distance of 11 kilometers.

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

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 26,112

Hi,

#If the difference between the circumference and radius of a circle is 37 centimeters, find its area.

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

Offline

**Monox D. I-Fly****Member**- From: Indonesia
- Registered: 2015-12-02
- Posts: 1,269

Actually I never watch Star Wars and not interested in it anyway, but I choose a Yoda card as my avatar in honor of our great friend bobbym who has passed away. May his adventurous soul rest in peace at heaven.

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 26,112

Hi,

(That was by oversight!)

The Solution #3871 is correct. Good work, Monox D. I-Fly!

#3872. If the area of a sector of a circle bounded by an arc of length

centimeters is equal to square centimeters, then find its radius.Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 26,112

Hi,

#3873. If

is taken as , find the distance in meters covered by a wheel of diameter 35 centimeters, in one revolution.Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 26,112

Hi,

#3874. If the perimeter of a circle is equal to that of a square, find the ratio of their areas.

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

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 26,112

Hi,

#3875. If the circumference of a circle increases from

to , then its area is(a) halved

(b) doubled

(c) tripled

(d) quadrupled

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

Offline

**Monox D. I-Fly****Member**- From: Indonesia
- Registered: 2015-12-02
- Posts: 1,269

Actually I never watch Star Wars and not interested in it anyway, but I choose a Yoda card as my avatar in honor of our great friend bobbym who has passed away. May his adventurous soul rest in peace at heaven.

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 26,112

Hi,

The solution #3875 is correct. Neat work, Monox D. I-Fly!

#3876. If the circumference and the area of a circle are numerically equal, then the diameter of the circle is

(a)

(b)

(c) 2

(d) 4

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

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 26,112

Hi,

#3877. If the area of a circle is equal to the sum of the areas of two circles of diameters 10 cm and 24 cm, then find the diameter of the larger circle (in cm).

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

Offline

**Monox D. I-Fly****Member**- From: Indonesia
- Registered: 2015-12-02
- Posts: 1,269

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 26,112

Hi,

The solution #3877 is correct. Good work, Monox D. I-Fly!

#3878. The ratio of the outer and inner perimeters of a circular path is 23:22. If the paths is 5 meters wide, then find the diameter of the inner circle.

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

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 26,112

Hi,

#3879. A copper rod of diameter 1 cm and length 8 cm is drawn into a wire of length 18 m of uniform thickness. Find the thickness of the wire.

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

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 26,112

Hi,

#3880. The largest sphere is carved out of a right circular cylinder of radius 7 cm and height 14 cm. Find the volume of the sphere.

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

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 26,112

Hi,

#3881. The diameter of a metallic sphere is equal to 9 cm. It is melted and drawn into a long wire of diameter 2 mm having uniform cross-section. Find the length of the wire.

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

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 26,112

Hi,

#3882. Solve:

152x - 378y = -74,

-378x + 152y = -604.

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

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 26,112

Hi,

#3883. Solve:

.

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

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 26,112

Hi,

.

#3884. A box contains 90 discs which are numbered from 1 to 90. If one disc are drawn at random from the box, find the probability of it bearing

(i) a two digit number

(ii) a perfect square number

(iii) a number divisible by 5.

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

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 26,112

Hi,

#3885. Find the probability of a number selected from the number 1 to 25 is not a prime number when each of the given numbers is equally likely to be selected.

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

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 26,112

Hi,

#3886. Five cards - the ten, jack, queen, king, and the ace of diamonds, are well-shuffled with their face downwards. One card is then picked up at random.

(i) What is the probability of the card is the queen?

(ii) If the queen is drawn and put aside, what is the probability of the second card picked up is (a) an ace? (b) a queen?

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

Offline