PERCENTAGE & RATIO PROPORTION SET5

Q.1 Milk vendor has 2 cans of milk. First contains 25% water & rest milk. Second contains 50% water. How much milk should he mix from each of the container so as to get 12 litres of milk such that ratio is 3:5 ?
A) 4 litres
B) 5 litres
C) 6 litres
D) 7 litres
Ans. C
Let the cost of 1 litre milk be Re. 1
Milk in 1 litre mix. in 1st can = 3 litre, C.P. of 1 litre mix. in 1st can Re. 3
4 4
Milk in 1 litre mix. in 2nd can = 1 litre, C.P. of 1 litre mix. in 2nd can Re. 1
2 2
Milk in 1 litre of final mix. = 5 litre, Mean price = Re. 5
8 8
By the rule of alligation, we have:

C.P. of 1 litre mixture in 1st can   C.P. of 1 litre mixture in 2nd can

3
4
Mean Price
5
8
1
2

1
8
1
8

  Ratio of two mixtures = 1 : 1 = 1 : 1.
8 8
So, quantity of mixture taken from each can = 1 x 12 = 6 litres.
2
Q.2 We have 100 litres of Vodka & take 10 litre & add 10 litre of water. Then after 3 processes what is the quantity of Vodka ?
A) 27 litre
B) 28 litre
C) 29 litre
D) 30 litre
Ans. A
Original quantity is 100 & if we take 10 litre then 90% is left i.e. 0.9
Then, V=100*(0.9)3
Or V=72.9
Or water=100-72.9
=27.1 litre

Q.3 Tea worth Rs.126/kg & Rs.135/kg are mixed with third variety in ratio 1:1:2.If mixture is worth Rs.153/kg by the price of third variety/kg will be :
A) 175.5
B) 180.2
C) 175.1
D) 180.6
Ans. A
126      135      x
1kg      1kg      2kg

        153
Or 126+135+2x=4*153
Or 261+2x=612
2x=351
X=175.5

Q.4 Discount on Rs. 2562 due 4 months hence is Rs.122. Rate % is ?
A) 2%
B) 3%
C) 4%
D)5%
Ans. D
2562-122=2440
122*100  /2440=5%

Q.5 729 ml of mixture contains milk & water in the ratio of 7:2. How much water is to be added to get a new mixture containing milk & water in the ratio of 7:3 ?
A) 80 ml
B) 81 ml
C) 82 ml
D) 83 ml
Ans. B
Milk=729*7/9 = 567 ml
Water=729-567=162 ml
Or 567/162+x=7/3
Or 1701=134+7x
X=81 ml