NumericalModerate2 marks
6(c)
If (7m + 2n) / (7m - 2n) = 5 / 3, use properties of proportion to find
m : n
Topic: Shares, dividend and return
Previous-year question practice database
Answer
Exam answer
(7m+2n)/(7m−2n) = 5/3.
Using componendo and dividendo: [(7m+2n)+(7m−2n)] / [(7m+2n)−(7m−2n)] = (5+3)/(5−3)
14m/4n = 8/2 = 4.
7m/(2n) = 4 7m = 8n
m:n = 8:7.
Answer: 8:7.
Explanation
Apply componendo and dividendo to separate m and n.
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