Average of 4 numbers is 15. Fourth number is twice of second number and first number is 1 less than second number and third number is 1 more than the second number. Find the second number.
A16
B11
C12
D24
Answer:
C. 12
Read Explanation:
Let the second number is x
First number = x - 1
Third number = x + 1
Fourth number = 2x
Average number = [(x - 1) + x + (x + 1) + 2x]/4
15 = 5x/4
x = (15 × 4)/5
x = 12