I've got a puzzle for you!!!

[cameo]

There are 3 items for sale.To make it easier let's say they are crayons!
Blue crayons are �1 each.
Red crayons are �1 for 5.
Green crayons are �1 for 20.
You have to spend a total of �100 and buy a total of �100 crayons.
You must purchase a least once from each colour group, and you can't split amounts up, eg: 10 green crayons for 50p isn't allowed!

My friend gave me this puzzle last night ans she couldn't do it. She won't get the answer till tomorrow, so when I know i'll let you all know!!!

[Phil7]

Do you mean spend �100 and buy 100 crayons?

Can you check the numbers, because if you buy 1 lot of each you get 26 crayons for �3 - leaving 74 more to be bought for �97, but the most expensive are blue (74 for �74). So how is it possible?

[cameo]

Those were the numbers i was given, my friend was very exact.
And yes it's �100 and 100 crayons.
I'm starting to think it's a trick question, but I still can't figure out what the answer could be!!! Grrrrrr

[cameo]

SORRY!! I made a mistake,
Blue crayons are �1 each.
Red crayons are �5 for 1
Green crayons are �1 for 20.
yes you have to buy 100 crayons, and have to spend exactly �100.

[crofter]

It is impossible! Suppose you spend �x on blue crayons, �y on red and �z on green, then you will have (x + 5y + 20z) crayons and they will have cost you �(x + y + z).

You want x + 5y + 20z = 100 Equation (1)
And also x + y + z = 100 Equation (2)

Subtracting (2) from (1) gives 4y = -19z

If z is positive, then y is NEGATIVE!!!

[cameo]

Pardon?!?

[crofter]

With the revised problem , you buy 1 blue, 19 red and 80 green crayons!

[kettledrum]

You beat me to it Crofter!

[crofter]

kettledrum Time was on my side as I already had the simultaneous equations for the erroneous problem. They only needed tweaking before the solution drops out!

[esmerelda3]

I had assumed the mistake was that you had tobuy 1000 crayons at the original prices in which case it was 36 blue , 54red and 10 green

[cameo]

crofter - thanks and well done!!!