Question

Find out the value of the following expression by estimating each number to its nearest unit place:

$\frac{63.1\times 12.5}{6.9\times 12.4}$

• A. 9
• B. 9.75
• C. 9.5
• D. 10

Answer 1

The correct option is B 9.75

First, we round $63.1$ to the nearest unit. As tenth place digit of the number is $1$ and $1<5$ so, $63.1\approx 63$

Similarly,

$12.5\approx 13$ as the digit in the tenth place is $5$.

$6.9\approx 7$ as the digit in the tenth place is $9$.

$12.4\approx 12$ as the digit in the tenth place is $4$.

$\frac{63.1\times 12.5}{6.9\times 12.4}\approx$ $\frac{63\times 13}{7\times 12}$

$=\frac{(7\times 3\times 3)\times 13}{7\times 3\times 4}$

Cancelling the common terms from numerator and denominator, we get

$\frac{3\times 13}{4}=9.75$