A list of 17 numbers has an average of 342. When two numbers are deleted from the list, the average of the remaining numbers is 315.
- What is the sum of 17 numbers?
- What is the bigger number between the two numbers that have been deleted given that the difference between the two numbers is 1?
(a)
Sum of the 17 numbers
= 17 x 342
= 5814
(b)
Remaining numbers
= 17 - 2
= 15
Sum of the remaining numbers
= 315 x 15
= 4725
Sum of the two numbers
= 5814 - 4725
= 1089
Smaller number = 1 u
Bigger number = 1 u + 1
Total = 1 u + 1 u + 1 = 2 u + 1
2 u + 1 = 1089
2 u = 1089 - 1
2 u = 1088
1 u = 1088 ÷ 2 = 544
Bigger number
= 1 u + 1
= 544 + 1
= 545
Answer(s): (a) 5814; (b) 545