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?  Select the correct option:
A) $3,000
B) $4,000
C) $7,000
D) $11,000
E) $25,000
Let Mary's income increase by x, then the equation will be   15,000 + x= (55/100)* (15,000 + x + 18000 )   15,000 + x = (11/20) * (33,000 + x)   300,000 + 20x = 11x + 363,000   9 x = 63,000   x = 7,000   So, Answer will be $7,000
<result>C</result>
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?