A list of 18 numbers has an average of 331. When two numbers are deleted from the list, the average of the remaining numbers is 325.
- What is the sum of 18 numbers?
- What is the bigger number between the two numbers that have been deleted given that the difference between the two numbers is 2?
(a)
Sum of the 18 numbers
= 18 x 331
= 5958
(b)
Remaining numbers
= 18 - 2
= 16
Sum of the remaining numbers
= 325 x 16
= 5200
Sum of the two numbers
= 5958 - 5200
= 758
Smaller number = 1 u
Bigger number = 1 u + 2
Total = 1 u + 1 u + 2 = 2 u + 2
2 u + 2 = 758
2 u = 758 - 2
2 u = 756
1 u = 756 ÷ 2 = 378
Bigger number
= 1 u + 2
= 378 + 2
= 380
Answer(s): (a) 5958; (b) 380