Answer: 293 031: these are the numbers 20, 21, 22, 23 etc grouped into three digits.

Puzzle 1507

I once cashed a cheque at the bank. I had spent £1.20 before I realised the bank clerk had made a mistake. He had transposed the pounds with the pence. I now had exactly 7 times the value of the original cheque. What was the original cheque's value?