A list of 15 numbers has an average of 348. When two numbers are deleted from the list, the average of the remaining numbers is 305.
- 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 5?
(a)
Sum of the 15 numbers
= 15 x 348
= 5220
(b)
Remaining numbers
= 15 - 2
= 13
Sum of the remaining numbers
= 305 x 13
= 3965
Sum of the two numbers
= 5220 - 3965
= 1255
Smaller number = 1 u
Bigger number = 1 u + 5
Total = 1 u + 1 u + 5 = 2 u + 5
2 u + 5 = 1255
2 u = 1255 - 5
2 u = 1250
1 u = 1250 ÷ 2 = 625
Bigger number
= 1 u + 5
= 625 + 5
= 630
Answer(s): (a) 5220; (b) 630