Question

A box contains 50 blue, red and green balls, if 20% are blue and 50% are green, what is the number of the red balls?

Answer 1

Given :

Number of blue, red and green balls :- 50

Percent of blue balls :- 20%

Percent of green balls :- 50%

To find :

Total number of red balls

Solution :

To find the number of red balls, we should find the percent of red balls first.

Percent of red balls :

${\sf \dashrightarrow 100 - (20 + 50)}$

${\sf \dashrightarrow 100 - 70}$

${\sf \dashrightarrow 30\%}$

Now, let's find the number of red balls.

Number of red balls :

${\sf \dashrightarrow 30\% \: of \: 50}$

${\sf \dashrightarrow \dfrac{30}{100} \times 50}$

${\sf \dashrightarrow \dfrac{3}{10} \times 50}$

${\sf \dashrightarrow \dfrac{3 \times 50}{10} = \dfrac{150}{10}}$

${\sf \dashrightarrow \cancel \dfrac{150}{10} = 15}$

Hence, the number of red balls in the box is 15.