Correct Option: D

16 men = 20 women 4 men = 5 women.
Now, according to question,
16 men complete the work in 25 days.
∴ 1 man one day’s work

=	1
	25 × 16

∴ 4 men one day’s work

=	4	=	1
	25 × 16		100

Similarly,
1 woman one day’s work

=	1
	25 × 20

∴ 5 women one day’s work

=	5	=	1
	25 × 20		100

∴ 28 men

=	28	× 5 = 35 women
	4

[28 men + 15 women]
∴ 50 women one day’s work

=	50	=	1
	25 × 20		10

Therefore, 28 men and 15 women can complete the whole work in 10 days.
Aliter : Using Rule 12,
A = 16, B = 20, a = 25
A₁ = 28, B₁ = 15

Time taken =	a(A × B)
	A1B1 + B1A

=	25(16 × 20)
	28 × 20 + 15 × 16

=	25 × 320
	560 + 240

=	25 × 320	= 10 days
	800