Help with MG question please

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sutu123
Posts: 54
Joined: Sat Jun 15, 2013 10:03 pm

Help with MG question please

Post by sutu123 »

Hi, Can any one tell us how to calculate this question, is there any method you can use than trail and error.
2 shirts and 3tops cost £29
3 shirts and 1top cost £19
what is the cost of 1top.

Ans: £7

Thank you.
nyr
Posts: 1166
Joined: Thu Apr 04, 2013 11:39 am

Re: Help with MG question please

Post by nyr »

2 shirts and 3tops cost £29
3 shirts and 1top cost £19
We can think of these as equations.

From the second equation, we know that 9 shirts and 3 tops cost £57.
Now, from the first equation, to buy 7 additional shirts we have to pay £28 more (£57-£29), so each shirt cost £4.
Back to the second equation. 1 top costs £7 (£19 - 3x£4).

Or, you could always go through the mechanics of applying simultaneous equations.

nyr
sutu123
Posts: 54
Joined: Sat Jun 15, 2013 10:03 pm

Re: Help with MG question please

Post by sutu123 »

Hi, thanks for the explanation. I did show my ds, he did understand. But is there any simpler method to do these kind of sums.
nyr
Posts: 1166
Joined: Thu Apr 04, 2013 11:39 am

Re: Help with MG question please

Post by nyr »

2 shirts and 3tops cost £29
3 shirts and 1top cost £19
A simpler approach may be as follows:

Let's get the same number of shirts in each equation. We can achieve this by multiplying the top equation by 3 and the bottom equation by 2. So we have that:

6 shirts and 9 tops cost £87
6 shirts and 2 tops cost £38

Now we see that to buy 7 tops costs £87-£38 = £49. Therefore the cost of each top is £7.

Is that simpler?

nyr
sutu123
Posts: 54
Joined: Sat Jun 15, 2013 10:03 pm

Re: Help with MG question please

Post by sutu123 »

Thank you sooooo much, that is lot simpler.
sutu123
Posts: 54
Joined: Sat Jun 15, 2013 10:03 pm

Re: Help with MG question please

Post by sutu123 »

Thank you sooooo much, that is lot simpler.
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