Question

If 15 men can finish a piece of work in 20 days, however it takes 24 women to finish it in 20 days. If 10 men and 8 women undertake to complete the work, then they will take: 

(a) 20 days 

(b) 30 days 

(c) 10 days 

(d) 15 days

Answer 1

Correct option (a) 20 days

Explanation:

According to the question, 

15 men = 20 days 300 men = 1 das …..(i) 

24 women = 20 days 480 women = 1 days ….(ii) 

Compare equation (i) and (ii) 

300 men = 480 women 

5 men = 8 women…..(iii) 

10 men + 8 women = ? 

10 men + 5 men = ? 

15 men = ? 

15 men × 20 days = 15 men × x days x = 20 days

Alternate:-

15 M ×20 days = 24 W × 20 days

M/W = 8/5

So, 1 man work 8 units work in one day 

And 1 women work 5 units work in one day.

Total work = hence, (10 M+ 8 W) 

Work whole work in ‘D’ days

(10 M +8 W)× D = 15 × 8 × 20 

(10×8 + 8×5) × D = 15 × 8 × 20 

(80 + 40) × D = 15 × 8 × 20 

D = 20 days