When the average age of husband, wife and their son was 42 years, the son got married and a child was born just one year after marriage. When the child turned to be 5 years, the average age of the family becomes 36 years. What was the age of daughter-in-law at the time of marriage?

The average weight of a group of 20 boys was calculated to be 89.4 kg and it was later discovered that one weight was misread as 78 kg instead of 87 kg. The correct average weight is 

A group consists of 25 men and 20 women. The average weight of men is 48 kg and that of women is 30 kg. The average weight of the group is

A car travel to a place 150 km away at an average speed of 50 km/hr and returns it 30 km/hr. What is the average speed of the whole journey?

In an examination, 40% of the candidates write their answers in Urdu and the rest in Marathi. The average marks of the candidates writing in Urdu is 74 and the average marks of the candidates writing in Marathi is 77. What are the average marks of all the candidates? 

The average of x numbers is 48. If of the numbers are increased by 51 each and remaining are decreased by 71 each, then what is the new average?