Question

3. In what ratio do the three varieties of rice
costing Rs 6, Rs 8 and Rs 9 per 100 grams
should be mixed in order to obtain a
mixture costing Rs 84 per kg?
A) 2 : 3:4
B) 1:3:6
C) 1:2:5
D) 3:4:2
E) None of these​

Answer 1

Answer:

Step 1: Compute cost of 1 kg of the mixture

The resultant mixture is sold at a profit of 20%. The selling price is Rs.96/kg

i.e., cost + 20% of cost = 1.2 (cost) = Rs.96

=> cost of the mixture = 961.2 = Rs.80/kg.

Let the three variants be A, B, and C and let their cost per kg be Rs.60, Rs.75 and Rs.100 respectively.

The mean price falls between B and C.

Hence the following method should be used to find the ratio in which the 3 variants should be mixed.

Step 2: Find out the ratio of QA : QC using alligation rule QAQC = 100−8080−60 = 11 = 1 : 1

Step 3: Find out the ratio of QB : QC using alligation rule QBQC = 100−8080−75 = 41 = 4 : 1

Step 4: QC, the resultant ratio of variant 'C' can be found by adding the value of QC in step 1 and step 2 = 1 + 1 = 2.

The resultant ratio QA : QB : QC :: 1 : 4 : 2.