Question:
There are four numbersn1 n2 n3 n4 . n2 is 5 more than n1 and n4 is 11 more than n3. n1 is 23 less than n4 . The average of the 4 numbers is 22, what is the value of n1?
A16
B24
C17
D12
Answer:
D. 12
Explanation:
(n1 + n2 + n3 + n4)/4 = 22 n1 + n2 + n3 + n4 = 88 .... (1) n2 = n1 + 5 n4 = 11 + n3 n1 = n4 - 23 n4 = n1 + 23 n3 = n4 - 11 = n1 + 23 - 11 = n1 + 12 (1) = n1 + n1 + 5 + n1 + 12 + n1 + 23 = 88 4n1 + 40 = 88 4n1 = 88 - 40 = 48 n1 = 48/4 = 12