dvk007 wrote:
Mary’s annual income is $15,000 and John’s annual income is $18,000. By how much must Mary’s annual income increase so that it constitutes 55% of Mary and John’s combined income?
(A) $3,000
(B) $4,000
(C) $7,000
(D) $11,000
(E) $25,000
If Mary's income (after the increase) is 55% of the combined total, that means that John's income (which is fixed at 18,000), must be 45% of the total (T).
So \(18,000=.45t\), or \(t = \frac{18,000}{0.45} = 40,000\).
That means that Mary's new income would be \(40,000 - 18,000 = 22,000\), which is \($7,000\) more than she has now.
Answer: C