
investment
A person 'X' invests 'P' dollars at once. In 7.25 years, if the amount doubles, then what would be the amount in terms of 'P' for 29 years?
So, I see that every 7.25 years we have P+P. Now, 7.25 goes into 29 4 times. Thus, we should have (P+P)^4=(2P)^4=16P^2.
how does this look?

The investment 'P' will double 4 times in 29 years (29/7.25=4). So X would equal P(2^4). It would not equal 16P^2. For example...
Lets say that P equals 3.
3(2^4)=48 != (16(3))^2 = 2304
Besides that you are right, the simplification is off though. :)

A person 'X' invests 'P' dollars at once. In 7.25 years, if the amount doubles, then what would be the amount in terms of 'P' for 29 years?
The amount increased each year for about 10%
