Solve 3/8+1/20-1/40

$$\frac { 3 } { 8 } + \frac { 1 } { 20 } - \frac { 1 } { 40 }$$

Evaluate

$$\frac{2}{5}=0.4$$

Solution Steps

Least common multiple of 8 and 20 is 40. Convert \frac{3}{8} and \frac{1}{20} to fractions with denominator 40.

$$\frac{15}{40}+\frac{2}{40}-\frac{1}{40}$$

Since \frac{15}{40} and \frac{2}{40} have the same denominator, add them by adding their numerators.

$$\frac{15+2}{40}-\frac{1}{40}$$

Add 15 and 2 to get 17.

$$\frac{17}{40}-\frac{1}{40}$$

Since \frac{17}{40} and \frac{1}{40} have the same denominator, subtract them by subtracting their numerators.

$$\frac{17-1}{40}$$

Subtract 1 from 17 to get 16.

$$\frac{16}{40}$$

Reduce the fraction \frac{16}{40} to lowest terms by extracting and canceling out 8.

$$\frac{2}{5}$$

Factor

$$\frac{2}{5} = 0.4$$