Question

A bag contains 3 red and 5 white balls. Another similar bag contains 10 white balls and an unknown number of red balls. If the ratio of the red to the white balls is equivalent in both the bags, determine the number of red balls in the second bag.

• A. $5$
• B. $10$
• C. $6$
• D. $\frac{50}{3}$

Answer 1

The correct option is C $6$

Number of red balls in the first bag $=3$

Number of white balls in the first bag $=5$

The ratio is $3:5,$ which is the same as $\frac{3}{5}$.

The number of red balls in the second bag is unknown.

Number of white balls in the second bag $=10$

Since the fractions are equivalent, the result of their cross products is equal.

$\frac{3}{5}=\frac{Unknown}{10}$

$3\times 10=5\times Unknown$

$30=5\times Unknown$

$\frac{30}{5}=Unknown$

$Unknown=6$

This implies, the total number of red balls in the second bag is $6$.