What number should be added to each of 12, 20, 28 and 44 so that the resulting numbers will be in proportion?
Show answer & explanation
Correct answer: B
Explanation
Let the number = x
(12+x)/(20+x) = (28+x)/(44+x)
(12+x)(44+x) = (20+x)(28+x)
528+56x+x² = 560+48x+x²
8x = 32
x = 4