The average of the numbers 52, 87, k, 103, 48, (k+4), 51 is 63. What is the value of k?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 48.
Sum = 52 + 87 + k + 103 + 48 + (k + 4) + 51 = (345 + 2k + 4) = 345 + 2k
Average = 63
(345+2k)/7 = 63
⇒345 + 2k = 441
⇒2k = 96
⇒k = 48