Fine the volume of a largest sphere inscribed from the right circular cylindrical wood whose radius is 1 cm and height is 5 cm

Fine the volume of a largest sphere inscribed from the right circular cylindrical wood whose radius is 1 cm and height is 5 cm 
A. 4/3 pi cm3
B. 5/16 pi cm3
C. 5 pi cm3
D. 8 pi cm3

Ans: A
Explanation:
The radius of largest sphere inscribed from the cylinder of radius 1 cm is also 1cm.
Therefore Volume = 4/3 pi r3
= 4/3 pi (1*1*1) cm3
=4/3 pi cm 3 

The average of five numbers is 20. If we eliminate one number from it, the average will be reduced by 5. What is the number eliminated?
A.5
B. 40
C. 20
D. 15

Ans:B
Explanation:
5*20=100
4*15=60
100-60=40