Maths puzzle answer!

Well done everyone for giving the maths puzzle a go! It was tricky!
Have a look at the answer to see how you got on:

20 Golden rings answers

Queen Ratticus can really cause some confusion even

if you use a calculator. Remember, the queen could have paid

one million pounds or £1 for the first, doubling each time. The

second method works out like this:

Cost of each ring:

1. £1

2. £2

3. £4

4. £8

5. £16

6. £32

7. £64

8. £128

9. £256

10. £512

11. £1 024

12. £2 048

13. £4 096

14. £8 192

15. £16 384

16. £32 768

17. £65 536

18. £131 072

19. £262 144

20. £524 288

Not the answer!!

Helpful hint:

·       To add up the total, take the last number, double it and then subtract 1.

·       eg to add 1 + 2 + 4 + 8, double 8 which is 16, subtract 1 which leaves 15.

·       So.... the total for 20 rings is £525288

       doubled which is £1 048 576, subtract 1, which is:

       £1,048,575.

Answer: £1,048,575

So.... Queen Ratticus paid £48,575

more by paying the second way!