Question

State true or false:

Two consecutive whole numbers whose product is $72$ are $8$ and $10$.

• A. True
• B. False

Answer 1

The correct option is B False

Let the numbers be $a$ and $b$
$a-b=1$ or $a=b+1$
$ab=72$
Hence, $(b+1)b=72$
$b^2+b-72=0$
$b^2+9b-8b-72=0$
$(b+9)(b-8)=0$
$b=-9$ or $8$. Since, the numbers are positive hence $b=8$
and $a=b+1=8+1=9$