In a group of 5 friends, the sums of ages (in years) of each group of 4 of them are 124, 128, 130, 136 and 142. The age (in years) of the youngest of them is
The mean of n observations is x1. If the first observation is increased by 1, second by 2, and so on, then their mean is x2 . The value of x2 - x1 is
The average of marks obtained in 120 students was 35. If the average of passed candidates was 39 and that of failed candi- dates is 15, the number of candidates who passed the examination is:
The age of Mr. Bhagat in 2002 was 1 /90 of his birth year. What is his age in 2006 ?
Four numbers are written in a row. The average of first two numbers is 7, the average of the middle two terms is 2.3 and the average of the last two numbers is 8.4. The average of first number and the last number is
The sum of seven consecutive even numbers of a set is 532. What is the average of first four consecutive even numbers of the same set ?
The ages of Melwyn and Louis are in the ratio of 7 : 10 respectively. After 6 years the ratio of their ages will be 17 : 23. What is the difference in their ages ?
