problem31-solved.rb

#In England the currency is made up of pound, £, and pence, p, and there are eight coins in general circulation:

#1p, 2p, 5p, 10p, 20p, 50p, £1 (100p) and £2 (200p).
#It is possible to make £2 in the following way:

#1×£1 + 1×50p + 2×20p + 1×5p + 1×2p + 3×1p
#How many different ways can £2 be made using any number of coins?

# 200 = a*200 + b*100 + c*50 + d*20 + e*10 + f*5 + g*2 + h*1

counter = 0

for b in 0..(200/100)
    for c in 0..(200/50)
        for d in 0..(200/20)
            for e in 0..(200/10)
                for f in 0..(200/5)
                    for g in 0..(200/2)
                        for h in 0..(200/1)
                            sum = b*100 + c*50 + d*20 + e*10 + f*5 + g*2 + h*1
                            if sum == 200
                                counter += 1
                            end
                        end
                    end
                end
            end
        end
    end
end

puts counter + 1