A list of 15 numbers has an average of 346. When two numbers are deleted from the list, the average of the remaining numbers is 311.
- What is the sum of 15 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 15 numbers
= 15 x 346
= 5190
(b)
Remaining numbers
= 15 - 2
= 13
Sum of the remaining numbers
= 311 x 13
= 4043
Sum of the two numbers
= 5190 - 4043
= 1147
Smaller number = 1 u
Bigger number = 1 u + 3
Total = 1 u + 1 u + 3 = 2 u + 3
2 u + 3 = 1147
2 u = 1147 - 3
2 u = 1144
1 u = 1144 ÷ 2 = 572
Bigger number
= 1 u + 3
= 572 + 3
= 575
Answer(s): (a) 5190; (b) 575