In how many days can 12 women finish a work? Statement I: 10 men can complete the work in 12 days. Statement II: 2 men and 2 women working together can complete the whole work in 33.33 days Statement III: If 20 men work for 3 days and thereafter 10 women replace them, the remaining work in completed in 7.5 days

Statement I gives men's rate: 10 men complete in 12 days, so 1 man = 1/120 work/day. Statement II gives combined rate: 2 men + 2 women complete in 33.33 days (100/3 days), so 2m + 2w = 3/100 work/day. From I and II, we can find women's rate: 2*(1/120) + 2w = 3/100, giving 1 woman = 1/150 work/day. Thus 12 women take 12.5 days. Statement III with I also gives women's rate: 20m*3 + 10w*7.5 = 1 work. Since any two statements suffice, option C is correct.