Wednesday, September 28, 2011

Challenge Yourself Question 5 by Shawn Liew Hong Wei and Ryan Chew




(n x $1.60) + $0.80 = [(n+10)$0.70] + $0.10

= (n x $1.60) + $0.80 - $0.10 = [(n+10)$0.70] + $0.10 - $0.10

= (n x $1.60 + $0.70 = [(n+10)$0.70]

(n x $1.60) + $0.70 - $0.70 = [(n+10-1)$0.70]

= n x $1.60 = (n+9)$0.70

= $(1.60n) = $(0.7n+6.3)

$(1.60n - 0.7n) = $(0.7n + 6.3 - 0.7n)

= $(0.9n) = $6.30

10/9 * $0.9n = 10/9 * $6.30

= $n = $7

n = 7

i) Mrs Tan bought 7 mangoes

ii) 7($1.60) + $0.80 = $12

Mrs Tan had $12 to buy fruits

2 comments:

  1. EXCELLENT effort in presentation. Very clear and concise. Good representations. Good job in systematically expressing your thought process.

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  2. I see that you are using the 'normal' method: LHS and RHS and crossover. There's a shorter method to this question. If you wan you can come and find me. I use my 'accumulate' method. Well your steps are clear and systematical. Nice.

    Find Revised if:
    Revised = Yap Boon Pin

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