## .Sam. 3 years ago Math Quiz: A country currency consists of the following coins 1¢, 2¢, 5¢, 10¢, 25¢, 50¢. What is the most money you can have in coins and not be able to pay exactly \$1? It can be over a dollar

1. FoolForMath

Coin change problem.

2. UnkleRhaukus

i guess you could have 99 1¢ pieces

3. Limitless

This doesn't seem well-posed.

4. .Sam.

It can be over a dollar

5. Limitless

Then.. There is no limit on what you can pay.

6. Limitless

Or perhaps I am not understanding correctly. You can have \(100\) 1 cent pieces, \(1000\) 1 cent pieces, \(10,000\) 1 cent pieces etc.

7. UnkleRhaukus

one 50¢ and three 20¢ maybe

8. Limitless

9. lgbasallote

ohhh pop quiz *_*

10. vanihba

you can't hv 2 50's, 4 25's, 1 50's and 2 25's, 1 50's and 5 10's, 1 50 and 20 5's and so on....

11. UnkleRhaukus

oh there are no 20¢ s only 25¢

12. UnkleRhaukus

3×25¢ and 3×10¢ =\$1.05

13. UnkleRhaukus

*+4¢

14. UnkleRhaukus

\$1.09

15. vanihba

ans. is 124 cents?

16. .Sam.

@UnkleRhaukus nope :) , Hint: its greater than that

17. Limitless

50, 25, {10,10,10,10,10,10,10,10,10}, 5, {2,2} ?

18. Limitless

oops, nope.

19. RolyPoly

First at most 1 50 cents, since 2 50 cents coins = \$1 => \$0.5 Then, at most 1 25 cents coin , since 2 25 cents coins = \$0.5 => + 0.5 above = 1 (=> rejected) Now, we've got \$0.75 We can at most 4 \$0.1 coins. since 5 x \$ 0.1 = \$ 0.5 + 0.5 above = \$1 (=> rejected) Now, we have \$ 0.75 + \$ 0.4 = 1.15 We CAN'T have \$0.05 coin, since it 0.05 + 0.75 = 0.8 + 0.2 = 1 (=> rejected) we can have at most 4\$0.02 coins, since 5x^0.02 = \$0.1 and 0.1+ 0.4 = 0.5 (rejected) Now we have 1.23 No 0.01 ... 1.23?

20. .Sam.

@RolyPoly is correct :D

21. RolyPoly

Yay!!!~

22. vanihba

50,25, 10, 10,10,10,2,2,2,2? oops 123

23. RolyPoly

*No 0.01 since 0.01 + 0.02 + 0.02 = 0.05, that is similar to 0.05 case (=> rejected)

24. Limitless

Thanks for the nice problem, .Sam.

25. .Sam.

np :)

26. RolyPoly

typo: we can have at most 4\$0.02 coins, since 5 x 0.02 = \$0.1 and 0.1+ 0.4 = 0.5 (rejected)