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0 sats \ 4 replies \ @Scroogey OP 9h \ on: Secondary school math puzzle science
Since it was solved so quickly, here's the most difficult one in the set (it was marked as difficult, and not mandatory), which made me fetch pen and paper:
Jimmy was 12 when Tom was as old as Jimmy is now.
Thus, Jimmy is 18 now, because 6 years ago Jimmy was 12 and Tom was 18.
I did guess and check again, haha.
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That's correct, but again there is an equation to be found and solved :)
There are two points in time, now and then.
We define
x as Jimmy's age now.
"Then" is when Tom was x years old.| Person | Now | Then |
|---|---|---|
| Tom | 24 | x |
| Jimmy | x |
To get from now to then (reading Tom's line) we subtract 24 and add x, hence the bottom right cell is
x-24+x = 2x-24.| Person | Now | Then |
|---|---|---|
| Tom | 24 | x |
| Jimmy | x | 2x-24 |
Now the equation is simply
2 \times (2x - 24) = 24, or x = 18.reply
Haha I basically stumbled upon my answer as I was trying to figure out what the right equation is
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