School-Safe Puzzle Games

## Pokemon obsessions

Now, this  question (similar to one I just saw in a 5th grade math book) is most definitely not directed at our Mega Math Geniuses.  It is not a really hard complicated math puzzle, but nonetheless, it is  somewhat tricky. If it were made into a multiple choice question, I bet

a large percentage of you might even rush into picking a “good” wrong answer.  In any case, it makes for great mind exercise for anyone at or above the 4th grade level. Teachers can try it on their students, and anyone much older can still use it to sharpen their brain. Especially if you try to solve without formal Algebra, and without using any pen or paper…

Aiden has 85 Pokemon cards.  Addison has 90 Pokemon cards. Last week, Aiden traded 17 cards to Addison for 13 of her cards.  How many cards did Addison have before the trade?

### 23 Comments to “Pokemon obsessions”

1. doar823 | Profile

I believe the answer is 86

2. seelesscacti | Profile

It’s gotta be 86, right?

3. Obiwan | Profile

Hard to see why answer is not 86…86 minus 13 + 17–>90!?

4. Migrated | Profile

Aiden last week had 85 cards. –> x

So this week it was x – 17 + 13 = 85 and y – 13 + 17 = 90
x + y = 175

So x = 175 – y.

Substituting x into the first equation, we get 175 – y – 17 + 13 = 85
y = 86

I hope I’m right.

5. Migrated | Profile

Sorry about my last post, the “last week” should read “this week”. I apologize for the error.

6. the_god_dellusion | Profile

ok no algebra or pen or paper. i do 17-13=4 then 90-4=86. hopefully i got it right

7. ruddwd | Profile

I am probably wrong as I am doing it off the cuff.. but here it goes: 86

8. ahsergio | Profile

addison had 94 and aiden 81 not using a paper makes me nervous, lol.

9. barftud | Profile

Surely it’s 86 – what’s the catch that I’m missing?

10. Shawn | PUZZLE GRANDMASTER | Profile

11. stathis_p | Profile

12. Margot | Profile

I believe Addison had 86 cards before the trade and Aiden had 89. Here are the equations I used to find those numbers:

Aiden:
x – 17 + 13 = 85
x = 89

y – 13 + 17 = 90
y = 86

13. scottk | Profile

86? 86 -13 = 73 + 17 = 90. pretty simple once you get it figured out, just takes a few second to get the order of things, especially with similar names.

14. michaelc | Profile

Are you smarter than a 4th grader?

Last week Aiden traded 17 cards for 13, or lost 4 cards.

Last week Addison traded 13 cards for 17 cards, or gained 4 cards.

That was something easy after trying to unscramble the letters “stripes” for 3 days. If only I had been more “persistent”, maybe the light would have finally come on! :O

aiden – 89

16. RK | Founder | Profile

86 is correct. Several non-math people I showed it to had a hard time getting the answer, even with ample time…

17. ahsergio | Profile

I’ve inverted the whole thing, i considered 85 and 90 as the starting situation, not the final one. thats quite tricky, for me at least

18. cjjkrenzbgt | Profile

If u think the answer is 90-4=86, is wrong.

Ive calculated the answer is 99.
IF Addison lost 13 and get 4, then the calculate is like this:
90+13-4=103-4=99.
SO, 99-13+4=90

i wonder if i wrong. . . (OR right)

19. cjjkrenzbgt | Profile

“SORRY im wrong calculation. OH NO
And its right who answer 86. (IM a big fail :P )