A list of 13 numbers has an average of 342. When two numbers are deleted from the list, the average of the remaining numbers is 308.
- What is the sum of 13 numbers?
- What is the bigger number between the two numbers that have been deleted given that the difference between the two numbers is 4?
(a)
Sum of the 13 numbers
= 13 x 342
= 4446
(b)
Remaining numbers
= 13 - 2
= 11
Sum of the remaining numbers
= 308 x 11
= 3388
Sum of the two numbers
= 4446 - 3388
= 1058
Smaller number = 1 u
Bigger number = 1 u + 4
Total = 1 u + 1 u + 4 = 2 u + 4
2 u + 4 = 1058
2 u = 1058 - 4
2 u = 1054
1 u = 1054 ÷ 2 = 527
Bigger number
= 1 u + 4
= 527 + 4
= 531
Answer(s): (a) 4446; (b) 531