Categories

[Smart Math] Percentages Problem 19

Here’s and example of a SMART MATH problem for PERCENTAGES.

Problem

The annual increase in population of a town is 5% If the present population is 70560, what was it two years ago?

1. 64000
2. 64500
3. 66000
4. 66500
5. 67000

The Usual Method

Let the population of the town two years ago be ‘x’.

Hence, population now will be:

$x\times 1.05\times 1.05=70560$

$\therefore x=\frac{70560}{1.05\times 1.05}=\frac{70560}{1.1025}=64000$

(Ans: 1)

Estimated Time to arrive at the answer = 45 seconds.