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 312.
- 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 4?
(a)
Sum of the 15 numbers
= 15 x 348
= 5220
(b)
Remaining numbers
= 15 - 2
= 13
Sum of the remaining numbers
= 312 x 13
= 4056
Sum of the two numbers
= 5220 - 4056
= 1164
Smaller number = 1 u
Bigger number = 1 u + 4
Total = 1 u + 1 u + 4 = 2 u + 4
2 u + 4 = 1164
2 u = 1164 - 4
2 u = 1160
1 u = 1160 ÷ 2 = 580
Bigger number
= 1 u + 4
= 580 + 4
= 584
Answer(s): (a) 5220; (b) 584