Question

The average of Twelve
numbers is 55.5, the average of first four numbers is 53.5 and that four numbers is 54.6. The 10th number is greater than the 9th number by 3 but least the 11th and 12th numbers by 2 and 3 respectively,what is the average of the 10th and the 12th numbers ?​

Answer 1

Answer:

59.5

Step-by-step explanation:





Given, average of first four numbers = 53.4

Sum of first four numbers = 213.6

Sum of next four numbers = 54.6x4 = 218.4

Let 10th number is N

9th number = N-3

11th number = N+2

12th number = N+3

Sum of total numbers = 213.6 + 218.4 + N +N-3 + N+2 + N+3

666 = 432 + 4N +2

4N = 232

N = 58

10th number = 58 and 12th Number = N+3 = 61

Average of 10th & 12th No. = (58+61)/2 = 59.5