Guess a solution! It can sometimes pay off to guess a solution and see how it fits. This is especially smart when you can’t find a systematic approach.

Testing a solution shows you how you need to proceed for the next guess: Should you go up or down in value?

Jasmine, Martin and Qiang are 37 years in total. Martin is four years older than Jasmine. Qiang is three years younger than Jasmine. How old are they?

Here, you can try to guess Jasmin’s age. Then you also know how old Martin and Qiang are. If the sum is greater than 37, then Jasmine is younger than what you guessed. If the sum is less than 37, then Jasmine is older than what you guessed. By adjusting, you will reach the right solution.