780gmatpossible wrote:
explanation please
780gmatpossibleso we have 40 litres of mixture (water+chemichal) in the ratio 3:5 ,
hence 3x+5x = 40 --- > 8x=40 ---> x =5
plug in this value into equation 3 (5)+5(5) = 40
water is 15 litres
chemical is 25 litres
We are told that 0.02 % of water is evaporated within ten 10 days and 0.05% of chemical is evaporated withn 10 days
0.02*10 days = 0.20 WATER
AND
0.05 *10 = 0.5 CHEMICHAL
0.20 *15 = 3 (total amount of water evaporated for 10 days )
0.50*25 = 12.5 (total amount of chemical evaporated for 10 days) ( to make it simple I will round 12.5 to 12 in final calculation below to find total mixture evaporated)
total percentage of mixture evaporated \(\frac{(3+12)}{40}= 36%\)
the closest answer is C