OthersMaths PuzzleLogical ReasoningDirection Sense
Fresh Grapes contain 90% water by wt. Dried grapes contain 20% water by %age. What will b wt of dried grapes when we begin with 20 kg fresh grapes?
a) 2kg
b) 2.4kg
c) 2.5kg
d) none
please tell steps
Read Solution (Total 4)
2.5 kg
weight of water in fresh grapes is 18kg and grape is 2kg
in dried grapes , 2kg is grapes , so x/x+2 = 20%
x = 0.5
total = 2 + 0.5 = 2.5
14 years agoHelpfull: Yes(18) No(14)
Fresh grapes contain 90% of their wt as water, alrite. so wt of water in fresh 20 kg grape would be:
( 20/100) * 90 = 18 kg.
So the dry wt of grapes is 2 kg. This dry wt is not going to go watever you do with it.
now what would be the wt of dried grapes which contain 20% of water by wt?
suppose the total wt of dry grapes is W...
W= dry weight of grapes + 20% of W
=> W = 2kg + (W/100) * 20
=> W =2 kg + W/5
=> 2kg = W - W/5 = (5W - W)/5
=> 4W/5 = 2kg
=> W =(2*5)/4 =5/2 kg i.e. 2.5 kg
now the waight of water in dry grapes is 20 % of total weight which is 2.5 kg, so the wt of water would be:
wt of water= 20% of W= (W/100) * 20 = W/5 = 2.5/5 =(5/2)/5 = 5/ (2*5) = 5/10 = 0.5 kg
so the wt of water in dry grapes would be 0.5 kg...
11 years agoHelpfull: Yes(18) No(3)
( 20/100) * 90 = 18 kg.
So the dry wt of grapes is 2 kg.
now what would be the wt of dried grapes which contain 20% of water by wt?
suppose the total wt of dry grapes is W.
W= dry weight of grapes + 20% of W
=> W = 2kg + (W/100) * 20
=> W =2 kg + W/5
=> 2kg = W - W/5 = (5W - W)/5
=> 4W/5 = 2kg
=> W =(2*5)/4 =5/2 kg i.e. 2.5 kg
ans c (2.5kg)
9 years agoHelpfull: Yes(4) No(0)
( 20/100) * 90 = 18 kg.
weight of water in fresh grapes is 18kg and grape is 2kg
dried grapes contains 20% water
grapes with water= (20/100)=0.5kg
so,total weight is 0.5+0.5*4=2.5kg