A wall of 100 metres can be built by 7 men or 10 women in 10 days. How

1.	A wall of 100 metres can be built by 7 men or 10 women in 10 days. How many days will 14 men and 20 women take to build a wall of 600 metres ? (a) 15 (b) 20 (c) 25 (d) 30
Answer» (a) 15 According to question, 10 women = 7 men \(\therefore\) 20 women = 14 men 14 men + 20 women = 14 men + 14 men = 28 men. A wall of 100 m is built by 7 men in 10 days A wall of 100 m is built by 1 man in (10 × 7) days A wall of 1 m is built by 1 man in \(\frac{10\times7}{100}\)days (less length, less days) A wall of 600 m is built by 1 man in \(\frac{10\times7\times600}{100}\) days (more length,more days) A wall of 600 m is built by 28 men in \(\frac{10\times7\times600}{100\times28}\) days = 15 days.

A wall of 100 metres can be built by 7 men or 10 women in 10 days. How many days will 14 men and 20 women take to build a wall of 600 metres ? (a) 15 (b) 20 (c) 25 (d) 30

Answer»

(a) 15

According to question, 10 women = 7 men

\(\therefore\) 20 women = 14 men

14 men + 20 women = 14 men + 14 men = 28 men.

A wall of 100 m is built by 7 men in 10 days

A wall of 100 m is built by 1 man in (10 × 7) days

A wall of 1 m is built by 1 man in \(\frac{10\times7}{100}\)days

(less length, less days)

A wall of 600 m is built by 1 man in \(\frac{10\times7\times600}{100}\) days (more length,more days)

A wall of 600 m is built by 28 men in \(\frac{10\times7\times600}{100\times28}\) days = 15 days.