After every hour a number increases 15 % of its present value. How many times it will increase in 8

M4maths Previous Puzzles

24 Jun 2011 number

After every hour a number increases 15 % of its present value. How many times it will increase in 8 hours

OPtion

1) 9
2) 8
3) 7
4) 6
5) 5
6) 4
7) 3
8) 2
9) 1
10) None of these

Solution

Let the original number is x
after 15 % increment the new number will be 1.15x
After 8 hour the number will be (1.15^8)x = 3.06x = 3x (approx)
so increase % = (3x-x)*100/x = 200%
so number will increase 2 times

Correct Option: 8 Best Solution (1)