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#1 2008-08-21 07:05:09

tony123
Member
Registered: 2007-08-03
Posts: 229

How many

A group of 20 people pay a total of £20 to see an exhibition. The admission price is £3 for 2 adults, £2 for seniors and 50p for children. How many adults, seniors and children are in the group?

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#2 2008-08-21 07:26:23

TheDude
Member
Registered: 2007-10-23
Posts: 361

Re: How many

Let A be the number of adults, S be the number of seniors, and C be the number of children.  I don't know English currency, but I'll assume 50p is equal to half a pound.

A + S + C = 20
1.5A + 2S + 0.5C = 20
S = 20 - (A + C)
1.5A + 2(20 - (A + C)) + 0.5C = 20
1.5A + 40 - 2A - 2C + 0.5C = 20
40 - 0.5A - 1.5C = 20
0.5A + 1.5C = 20
A + 3C = 40

Assuming that you need an even number of adults (since the price is listed per 2 adults, rather than per adult) use trial and error to find the following possible solutions:
12C, 4A, 4S
10C, 10A
If you can have an odd number of adults then 13C, 1A, 6S and 11C, 7A, 2S also work.


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