Recently, packets of Amblers crisps have had ‘money-off’ coupons inside them. Some coupons

Question

are worth 9p, some are worth 14p and some are worth 20p.
George has been collecting these coupons. He has more 14p coupons than 9p coupons, and
more 9p coupons than 20p coupons. The total value of all of his coupons is exactly £1.50.
How many coupons has George collected?
Others have tried explaining, but I literally don't get this problem. I would appreciate a simplified answer.

Answer 1

20p < 9p < 14p

minimally ... 1 - 20p , 2 - 9p , 3 - 14p ... 80p total

add coupons to get to £1.50
... you can add as many 14p as you like
... adding 9p also adds 14p ... 23p each
... adding 20p also adds 9p and 14p ... 43p each

adding five 14p coupons gives £1.50