Q75
A small disc of radius r is cut out from a disc of radius R. The weight of the disc which now has a hole in it, is reduced to 2425 of the original weight. If R = xr, what is the value of x ?
A small disc of radius r is cut out from a disc of radius R. The weight of the disc which now has a hole in it, is reduced to of the original weight. If R = xr, what is the value of x ?
A.
4
B.
4.5
C.
24
D.
25
E.
None of these
AnswerAnswer: Option E
Solution
Answer: Option E
Solution:
Since weight of the disc is proportional to its area, we have :