WAEC 2017 Mathematics · Question 3

A sum of N18,100 was shared among 5 boys and 4 girls with each boy taking N20.00 more than each girl. Find a boy's share.

Options

A.N1,820.00
B.2,000.00
C.N2,020.00
D.N2,040.00

Answer: C. N2,020.00

Explanation written with AI and checked against the answer key

Analyze the question: A total of N18,100 is shared among 5 boys and 4 girls. Each boy gets N20 more than each girl. We need a boy's share. Concept: Let a girl's share be x. Then a boy's share is x + 20. Total of all shares = N18,100. Solution: Let a girl's share = x, so a boy's share = x + 20. 5(x + 20) + 4x = 18,100 5x + 100 + 4x = 18,100 9x = 18,000 x = 2,000 So a girl gets N2,000, and a boy gets 2,000 + 20 = N2,020. Check: 5 × 2,020 = 10,100 and 4 × 2,000 = 8,000. Total = 18,100 ✓ Tip: In "sharing" problems where one group gets extra, let the smaller share be x, express the other share in terms of x, then form one equation from the total. Always verify by plugging back in. Be careful not to stop at x, because option B (N2,000) is the girl's share, a common trap!

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