DXC Technology Allegations and Mixtures Questions and Answers Quiz-1

Solution : Here, we need to apply the formula P x [1 – (R / P)]ⁿ
P = Initial quantity of pure element = 20 liters
R = Quantity replaced every time = 1 liter
n = Number of replacements = 5
So, quantity of pure milk after 5 replacements = 20 x [1 – (1 / 20)]⁵
Quantity of pure milk after 5 replacements = 20 x (0.95)⁵ = 20 x 0.773780938 = 15.4756 liters
Therefore, percentage of pure milk left in the vessel after 5 replacements = (15.4756 / 20) x 100 = 77.378 %

Thus, ratio of quantities of cheaper and good quality rice = 10 : 5 = 2 : 1

Solution : Water in the 30 litre of mixture = 30 x 10/100 = 3 litres
Milk in the mixture = 30 – 3 = 27 litres
Let x litres of water is mixed.
Acc. to question
(3 + x)/(30 + x) = 25/100
4(3 + x) = 30 + x
12 + 4x = 30 + x
3x = 18
x = 6
Hence, 6 litres of water to be added in the mixture.

4 -> 25000
1 -> 6250
Hence, number of girls passed in the exam is 6250.

Solution : Acc. to question
SP of 1 kg of mixture = Rs 34.1
Profit = 10% = 10/100 = 1/10
SP = 1 + 10 = 11 unit
11 units ->34.1
1 unit -> 3.1
10 unit -> 31
We obtain the CP of the mixture Rs 31.
To obtain the ratio use alligation method

Hence, the ratio in which he mixed is 3:2

To obtain the ratio in which A and B mixed we apply alligation rule


Hence, the required ratio is 3:10.

To obtain the ratio in which A and B mixed we apply alligation rule


Hence, the required ratio is 3:10.

Alloy A 40 kg contains lead and copper in ratio 3:2
So, 3+2 = 5
5 unit -> 40
1 unit -> 8
2 unit -> 16
Amount of copper in alloy A is 16 kg.
Alloy B contains copper and tin in ratio 1:3
So, 1+3 = 4
4 unit -> 100
1 -> 25
Amount of copper in alloy B is 25 kg
Hence, amount of copper in the new alloy is 16 + 25 = 41 kg.

Cost Price of 1kg of Type 1 sugar = 6200 p. Cost Price of 1kg of Type 2 sugar = 7200 p. Mean Price of of 1 kg of mixture = 6450 p. According to the Rule of Alligation, (Quantity of Cheaper):(Quantity of Dearer) = (CP of dearer - Mean Price):(Mean Price - CP of cheaper) Therefore, the required ratio = (7200-6450):(6450-6200) = 750:250 = 3:1.

Cost Price of 1 litre of water = Rs 0. Cost Price of 1 litre of milk = Rs 12. Mean Price of Mixture = Rs 8. According to the Rule of Alligation, (Quantity of Cheaper):(Quantity of Dearer) = (CP of dearer - Mean Price):(Mean Price - CP of cheaper) Therefore, Water:Milk = (12-8):(8-0) = 4:8 = 1:2.