Aptitude Day 157

Problems on Average:

 1. The average of 5 consecutive numbers is 15. The largest of these numbers is:

Solution:

                 [x+(x+1)+(x+2)+(x+3)+(x+4)]/ 5 = 15

                 5x + 10 = 75

                 x = 13.

                 The largest number is x+4 = 17.

2. The average of 3 consecutive odd numbers is 9. What’s the difference between the highest and lowest numbers?

Solution:

                 [x+(x+2)+(x+4)]/ 3 = 9

                 3x+9 = 27

                 x =7.

               The difference between the highest and lowest numbers = (x+4)-x

                                                                                                         = (7+4)-7

                                                                                                         = 4.