Question

Fill the blank space: $5\times ...............=31\times ..........$

• A. $5,31$
• B. $31,5$
• C. $5,5$
• D. $31,31$

Answer 1

The correct option is B $31,5$

Whole numbers are commutative under multiplication.

So, for any whole numbers $a$ and $b$ $\Rightarrow$ $a\times \underset{–}{b}=\underset{–}{b}\times a$. [Note that here the first - term becomes the second term and second term becomes the first term]
$\therefore 5\times ..............=\underset{–}{31}\times ............$
$\therefore 5\times 31=31\times 5$
Thus, the missing numbers are $31,5$.