number puzzle

[bobobalde111]

a boy spent �180 on footballs from a shop if he had bought them from the shop next door he would have paid �3 more per ball so would have got two less balls for his money
how many did he buy in the first shop

[crofter]

he bought 12 balls at �15 = �180
At the next shop he would only be able to buy10 at �18.

[crofter]

Method of solution:
Suppose he first buys N balls at �P then NxP = 180
and (N - 2) (P + 3) =NxP which becomes 2P = 3N - 6
Multiplying this second equation by N : 2NxP = 3N^2-6N
But NxP - 180, so we finally get 2x180 = 3N^2 -6N
Solving N^2 -2N - 120 = 0
That is (N-12)(N+10)= 0
Hence N = 12 (or N = -10)
So he buys N = 12 balls!

[bobobalde111]

glad you are back and are well
look forward to your solutions every week

[crofter]

I now have a PC up and running at home - just so that I can be first to answer your Tuesday morning teaser!

Please note that next week I shall be on the Costa del Sol (just one week) for late break!