Question

There are $222$ red balls in a basket. A boy takes out 6 red balls from it and replaces them by $12$ white balls. He continues to do so, till all red balls are replaced by white balls. Then the number of white balls put in the basket is _____.

Answer 1

Let n be the number of steps.
According to question, $222-6\times n=0$
$\Rightarrow$ $6n=222$ $\Rightarrow$ = $\frac{222}{6}$ $=37$
Now, number of white balls added in one step $=12$
$\therefore$ Number of white balls added in 37 steps $=12\times 37=444$