Aptitude Day 151

Problems on Average:

1. The average of 3 consecutive even number is 20. Find the smallest of these numbers.

Solution:

                Let the numbers be x, x+2 and x+4 respectively.

               Average = Sum of observations/ Number of observations

                        20 = x+x+2+x+4/3

                        60 = 3x+6

                          x = 18.

               The smallest number is x = 18.

2. Anna obtained 70, 85, 90, 88 and 73 marks (out of 100) in 5 subjects. What are her average marks?

Solution:

                 Average = Sum of observations/ Number of observations

                               = 70+ 85+ 90+ 88+ 73/5

                               = 406/5

                               = 81.2.