If 2/5+2/10=(N+1)/(N+5), then find the value of N.

Correct option is A

Given:

​$$\frac{2}{5} + \frac{2}{10} = \frac{N+1}{N+5}$$​​

Solution;

​$$\frac{2}{5} + \frac{2}{10} = \frac{N+1}{N+5} \\\\\frac{4}{10} + \frac{2}{10} = \frac{6}{10} \\\\\frac{6}{10} = \frac{N+1}{N+5} \\$$ 

cross multiplication 

​$$6N + 30 = 10N + 10 \\6N - 10N = 10 - 30 \\-4N = -20 \\N = \frac{-20}{-4} = 5$$​​