A list of 13 numbers has an average of 340. When two numbers are deleted from the list, the average of the remaining numbers is 309.
- 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 3?
(a)
Sum of the 13 numbers
= 13 x 340
= 4420
(b)
Remaining numbers
= 13 - 2
= 11
Sum of the remaining numbers
= 309 x 11
= 3399
Sum of the two numbers
= 4420 - 3399
= 1021
Smaller number = 1 u
Bigger number = 1 u + 3
Total = 1 u + 1 u + 3 = 2 u + 3
2 u + 3 = 1021
2 u = 1021 - 3
2 u = 1018
1 u = 1018 ÷ 2 = 509
Bigger number
= 1 u + 3
= 509 + 3
= 512
Answer(s): (a) 4420; (b) 512