Solve 1/3.9+1/5+1/10

$$\frac{ 1 }{ 3.9 } + \frac{ 1 }{ 5 } + \frac{ 1 }{ 10 }$$

Evaluate

$$\frac{217}{390}\approx 0.556410256$$

Solution Steps

Expand \frac{1}{3.9} by multiplying both numerator and the denominator by 10.

$$\frac{10}{39}+\frac{1}{5}+\frac{1}{10}$$

Least common multiple of 39 and 5 is 195. Convert \frac{10}{39} and \frac{1}{5} to fractions with denominator 195.

$$\frac{50}{195}+\frac{39}{195}+\frac{1}{10}$$

Since \frac{50}{195} and \frac{39}{195} have the same denominator, add them by adding their numerators.

$$\frac{50+39}{195}+\frac{1}{10}$$

Add 50 and 39 to get 89.

$$\frac{89}{195}+\frac{1}{10}$$

Least common multiple of 195 and 10 is 390. Convert \frac{89}{195} and \frac{1}{10} to fractions with denominator 390.

$$\frac{178}{390}+\frac{39}{390}$$

Since \frac{178}{390} and \frac{39}{390} have the same denominator, add them by adding their numerators.

$$\frac{178+39}{390}$$

Add 178 and 39 to get 217.

$$\frac{217}{390}$$

Factor

$$\frac{7 \cdot 31}{2 \cdot 3 \cdot 5 \cdot 13} = 0.5564102564102564$$