Question

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
(c) 25
(b) 20
(d) 30​

Answer 1

Answer:

ANSWER

According to question 10 women = 7 men ∴ 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 x 7) days

A wall of 1 m is built by 1 man in

100

10×7

days (less length, less days)

A wall of 600 m is built by 1 man in

100

10×7×600

days (more length, more days)

A wall of 600 m is built by 28 men in

100×28

10×7×600

days = 15 days

Answer 2

=efficiency of (14 men+20 women)

=(14×10)+(20×7)(14×10)+(20×7)

=140+140140+140

=280

Let 'D' days taken.

$\frac{(7 \times 10) \times 10}{100} = \frac{280 \times d}{600}$

d= 15 Days .