Comprehension A student goes shopping by bicycle and travels the distance of 10 km to reach the shop in 50 minutes. He buys a cylinder whose volume of

Question

How much speed did he increase during returning from the shop?
1. 3 km/hr
2. 2 km/hr
3. 4 km/hr
4. 5 km/hr
5. 1 km/hr

Answer 1

Correct Answer - Option 1 : 3 km/hr

Given:

The distance is travelled by him = 10 km

Reaching time = 50 minutes

⇒ (5/6) hours

The volume of a cylinder = 4620 m³

The volume of a cone = (1/7) × the volume of a cylinder

And the height of a cone = 10 m

Reduce time = (50 - 10)

⇒ 40 minutes

⇒ 40/60 hours

⇒ 2/3 hours 

Formula used:

Speed = (Distance/Time)

The volume of cylinder = πr²h

The curved surface area of a cylinder = 2πrh, where r is the radius of a cylinder and h is the height of a cylinder.

The volume of a cone = (1/3)πR2H, where R is the radius of a cone, H is the height of a cone and π is 22/7

The slant height of a cone = √(height² + radius²)

Calculation:

The speed when he went shopping = [(10)/(5/6)]

⇒ 12 km/hr

And the speed during returning = [(10)/(2/3)]

⇒ 15 km/hr

Increased speed = 15 - 12

⇒ 3 km/hr

∴ His increased speed was 3 km/hr