Aptitude Day 173

Problems on Average:

1. The average weight of 3 girls A, B and C is 16(1/3) kg, while the average weight of 3 girls B, D and E is 50 kg. What’s the average weight of A, B, C, D and E?

Solution:

                 A+B+C/3 = 16(1/3)

                 B+D+E = 50

                Adding the above 2 equations, we get

                A+2B+C+D+E = 49+50 =99.  

                The weight of B is required in order to calculate the average. So the given data is inadequate.

2. The average temperature of the town in the 1^st 4 days of a month was 38 degrees. The average for the 2^nd, 3^rd, 4^th and 5^th days was 40 degrees. If the temperature of the 1^st and 5^th days were in the ratio 3:4, then what’s the temperature on the 5^th day?

Solution:

                 The sum of the temperature of the 1^st 4 days = 38*4 = 152.

                 The sum of the temperature of the last 4 days = 40*4 = 160.

                Temperature of  5^th day – Temperature of 1^st  day = 160-152 = 8 degrees.

                4x-3x =8

                x = 8. 

               The temperature on the 5^th day is 4x = 32 degrees.