Pre Algebra: Word Problems with Fractions

1. E

$$\eqalign{\dfrac{1}{3}+\dfrac{1}{5}+\dfrac{3}{10}&=\dfrac{5}{6}\\\dfrac{6}{6}-\dfrac{5}{6}&=\dfrac{1}{6}}$$

2.B

$$\eqalign{\dfrac{1}{3}+\dfrac{1}{5}&=\dfrac{8}{15}\\\dfrac{15}{15}-\dfrac{8}{15}&=\dfrac{7}{15}}$$

3. B

$$\eqalign{\dfrac{1}{3}+\dfrac{1}{5}&=\dfrac{8}{15}\\\dfrac{15}{15}-\dfrac{8}{15}&=\dfrac{7}{15}\\\dfrac{7}{15}\times\text{students}&=21\\\div\dfrac{7}{15}\qquad\qquad&\;\div\dfrac{7}{15}\\\text{students}&=45\\45 + 1&= \text{students plus teacher}\\46&=\text{students plus teacher}}$$

4.$\dfrac{5}{24}$

$$\eqalign{\dfrac{1}{8}+\dfrac{2}{3}&=\dfrac{19}{24}\\\dfrac{24}{24}-\dfrac{19}{24}&=\dfrac{5}{24}}$$