Question

1/20+1/30+1/42+1/56+1/72+1/90=?

Answer 1

$(\frac{1}{20}+\frac{1}{30})+(\frac{1}{42}+\frac{1}{56})+(\frac{1}{72}+\frac{1}{90})\\ \\=\frac{3+2}{60}+\frac{4+3}{168}+\frac{5+4}{360}\\ \\=\frac{1}{12}+\frac{1}{24}+\frac{1}{40}\\ \\=\frac{10+5+3}{120}=\frac{3}{20}=0.15$

Answer 2

Answer:

$\frac{3}{20}$

Step-by-step explanation:

Given : $\frac{1}{20}+\frac{1}{30}+\frac{1}{42}+\frac{1}{56}+\frac{1}{72}+\frac{1}{90}$

To Find : Solve

Solution :

$\frac{1}{20}+\frac{1}{30}+\frac{1}{42}+\frac{1}{56}+\frac{1}{72}+\frac{1}{90}$

Take LCM of 20,30,42,56,72,90

LCM = 2520

$\frac{126+84+60+45+35+28}{2520}$

$\frac{378}{2520}$

$\frac{3}{20}$

Hence $\frac{1}{20}+\frac{1}{30}+\frac{1}{42}+\frac{1}{56}+\frac{1}{72}+\frac{1}{90}=\frac{3}{20}$