Question

What is the value of the number in the blank box given above?

• A. 21

Answer 1

The correct option is A 21
The number 7 can also be written as $3\times 4$.
We can find the value of $7\times 3$ by using tables of 3 and 4.

Using the table of 3 and 4, we get

$7\times 3$ $=(3+4)\times 3=(3\times 3)+(4\times 3)=9+12=21$

The same can be found using tables of 2 and 5 also.

$\therefore$ The number in the blank box is 21.