If there are 50 mangoes in a box, how will you write the total number of mangoes in terms of the number of boxes? (Use $ b $ for the number of boxes.)

Given:

There are 50 mangoes in a box.

To do:

We have to find the rule which gives the number of mangoes in terms of the number of boxes.

Solution:

Let the number of boxes be $b$.

The number of mangoes in a box $=50$. 

This implies,

The total number of mangoes $=$ Number of mangoes in a box $\times$ Number of boxes.

$=50\times b$

$=50b$.

Therefore, the required rule for the total number of mangoes is $50b$.