Explanation:

Quantity 1:

In 8 days Anil does=1/3 rd work

In 1 day=1/24 thwork

Rakesh’s one day work=60% of 1/24=1/40 thwork

Remaining work=1-1/3=2/3

Anil & Rakesh’s one day’s work

=1/24+1/40=1/15 th

2/3 rd work=15×2/3=10 days

Quantity 2:

Work completed by 8M + 4W in 2 days = 2 ×1/6=1/3

Work done by 1 man = work done by 2 women

8 men + 4 women = (16 women + 4 women) = 20 women

8 men + 4 women = (8 men + 2 men) = 10 men

Work done by 20 women in 1 day = 1/20× 6 =1/120

Work done by 10 men in 1 day =1/10× 6 =1/60

As 4 men left and 4 new women joined, so 4M + 8W = 4 ×1/60+ 8 ×1/120=1/15+1/15=2/15

Work to be done = 1 -1/3=2/3

No of days required =(2/3)/(2/15)= 5 days.

Hence, option 3 is the correct answer.