averages Model Questions & Answers, Practice Test for ibps rrb po prelims

The average temperature for the first four days of a week is 40.2°C and that of the last four days is 41.3°C. If the average temperature for the whole week is 40.6°C, then the temperature on the fourth day is

Out of 250 observations, the first 100 observations have mean 5 and the average of the remaining 150 observations is $25/3$. What is the average of the whole group of observations ?

In a class, the average height of 35 girls was measured 160 cm. Later on, it was discovered that the height of one of the girl was misread as 144 cm, while her actual height was 104 cm. What was the actual average height of girls in the class ? (rounded off to two digits after decimal)

The average weight of 8 persons is increased by 2.5 kg when one of them who weighs 56 kg is replaced by a new man. The weight of the new man is

Ten (10) years before, the ages of a mother and her daugther were in the ratio 3 : 1. In another 10 years from now, the ratio of their ages will be 13 : 7. What are their present ages?