What is the most efficient way to solve:
P + G = 9
2*G + A = 19
A + P = 7

I can do it but it takes too many steps.

Here is how solved it (feel free to try to solve it first before reading my solution below!):
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1) Look at the first 3 lines and determine the minimum and maximum value for each fruit:
-Pineapple: 0~7.
-Grape: 2~7 (It cannot be lower than 2, because Pineapple + Grape = 9 and we know that Pineapple is 0~7).
-Apple: 0~7.

2) We know Grape is between 2~7, then:
-Max Value (Apple) = 19 - 2x2 = 15
-Min Value (Apple) = 19 - 2x7 = 5

3) We know Apple can't be higher than 7 (because Apple + Pineapple = 7), so:
OK: Apple is between 5 and 7.
OK: Grape is between 2 and 7.

4) We know that Apple + Pineapple = 7 and Apple is between 5 and 7, then:
OK: Pineapple is between 0 and 2.
UPDATE: Grape is 7 (because Grape + Pineapple = 9), since Pineapple is 0~2 and Grape is 2~7.
UPDATE: Apple is 5, since 2x7 (Grape) + Apple = 19
UPDATE: Pineapple is 2. Proof: 7 (Grape) + Pineapple = 9. And 5 (Apple) + Pineapple = 7

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ANSWER: 7 + 5 + 2 = 14

is there anyone who cant solve this puzzle?

matte pussel för de smarta brevarna ^^