The ratio of efficiences of a man and a woman is 5 : 3. If 18 men take 24 days to complete a work, working 15 hrs a day, how much time will 10 women take to complete the same work working 12 hrs a day?

78 days  60 days  90 days 45 days

90 days

M X Eff. x Hours x Days = constant (when the work is the same)  18M x 5 x 15 x 24 = 10W x 3 x 12 x days  No. of days = 90