S varis directlyR varis &T varis inversely asR varis,R=10 S=30 &T=5,If R is changed to25 then valuT?

Question

option 1:2

option 2:10

option 3:4

option 4:8

option 5:None of these

Answer 1

R changes from 10 to 25 which is an increase factor of 25/10=5/2.
T=5 when R=10, so because it changes inversely as R changes, we need to change T by 2/5, i.e., 2/5*5=2 (option 1).
(S doesn't come into it.)