Question

The number of positive integral solution of $abc = 30$ is

• A. 30
• B. 27
• C. 8
• D. None of these

Answer 1

Answer: (B)

27

Answer 2

We have : $30 = 2 \times 3 \times 5$.
So, $2$ can be assigned to either $a$ or $b$ or $c$
i.e. $2$ can be assigned in $3$ ways.
Similarly, each of $3$ and $5$ can be assigned in $3$ ways.
Thus, the number of solutions is $3 \times 3 \times 3 = 27$.