In a contest, two people will have to answer 80 questions each. They score 3 points for each correct answer. The contest has not ended yet. Each person has already answered 60 questions. Person C has answered 45% of the first 60 questions correctly. Person D has answered 50% of the first 60 questions correctly. What is the minimum number of points that Person C must get from the last 20 questions to win the contest?

	Person C	Person D
Current total score	81	90
Additional score if the remaining questions are answered correctly	+ 72	+ 60
Final total score	153	150
	Winner

Score that Person C has earned so far
= 45% x 60 x 3
= ⁴⁵₁₀₀ x 60 x 3
= 81

Score that Person D has earned so far
= 50% x 60 x 3
= ⁵⁰₁₀₀ x 60 x 3
= 90

Remaining questions that each person has to answer
= 80 - 60
= 20

If Person D answers the last 20 questions correctly, the additional score that he will earn
= 20 x 3
= 60

Total score that Person D will earn after answering all the questions
= 90 + 60
= 150

Number of points that Person D is leading Person C by
= 150 - 81
= 69

For Person C to win the contest, the number of points he has to earn
= 69 + 3
= 72

Answer(s): 72