13 Catherine ordered a basket of fruits containing apples, oranges and pears only. $\frac{5}{16}$ of the fruits are apples. 80% of the remaining fruits are oranges. The other 11 fruits are pears. Find the number of apples in the basket. Answer ___ apples

1. Find the fraction of fruits remaining after the apples are removed.

Fraction of fruits that are not apples:

$1-\frac{5}{16}=\frac{11}{16}$

2. Find the fraction of the total basket that are pears.

Since $80\%$ of the remaining fruits are oranges, the pears are $20\%$ of the remaining fruits.

$20\%\times \frac{11}{16}=\frac{20}{100}\times \frac{11}{16}=\frac{1}{5}\times \frac{11}{16}=\frac{11}{80}$

So pears are $\frac{11}{80}$ of all the fruits.

3. Use the number of pears to find the total number of fruits, then find the number of apples.

The $11$ pears represent $\frac{11}{80}$ of the total number of fruits.

Let the total number of fruits be $T$.

$\frac{11}{80}T=11$

$T=11\div \frac{11}{80}=80$

Number of apples:

$\frac{5}{16}\times 80=25$