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# [Smart Math] Ratio Proportion Problem 7

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

### Problem

If 5/7 of an integer is 1125, 4/7 of the same integer will be…

1. 5625
2. 4500
3. 7875
4. 900
5. 1124

### The Usual Method

5/7 of x = 1125

$\therefore x=\frac{1125\times 7}{5}$

= 225 x 7 = 1575

$\therefore$4/7 of 1575 = $\frac{1575\times 4}{7}$= 900

(Ans: 4)

Estimated Time to arrive at the answer = 45 seconds.

### Using Technique

Simply find those options that are multiples of 4. This is because the answer is $\frac{4}{7}$x some integer. In this case, the multiples of 4 are options ‘2’, ‘4’ and ‘5’. Of these, option ‘2’ can be eliminated as $\frac{4}{7}$x some integer < $\frac{5}{7}$ x some integer, but in case of option ‘2’, 4500 > 1125.