Question

Identify the number that can be multiplied to make the fraction $6\frac{1}{15}$ a terminating decimal number.

• A. $2$
• B. $3$
• C. $5$
• D. $51$

Answer 1

Answer: (B), (D)

$51$

The number $6\frac{1}{15}$ has $15$ in its denominator.

$15=3\times 5$

To make the fraction a terminating decimal, we need to eliminate $3$ in the denominator by multiplying a number which is a multiple of $3.$

For example,
$6\frac{1}{15}\times 3=\frac{6\times 15+1}{3\times 5}\times 3=\frac{91}{5}$

Now, the denominator is a multiple of $5$. Hence it will result in a terminating decimal number.

Similarly, $51$ is also a multiple of $3.$
So, it can be multiplied with $6\frac{1}{15}$ to eliminate 3 from its denominator.
$6\frac{1}{15}\times 51=\frac{6\times 15+1}{3\times 5}\times 3\times 17=\frac{91\times 17}{5}$