When my age is divided by 3, the remainder is 1. when my age is divided by 5, the remainder is 3. when my age is divided by 7, the remainder is 1. how old am i?

You're age is 43
I take the multiples of 7
M{7,14,21,28,35,42...}
I add 1 because you need a remainder of 1 and then try to get the others 2 divisions to work
i choose 7 because its the biggest number it takes a lower amount of time

What’s the equation you are trying to solve to get x?

The answer would be a