Mike and Jasmine have a combined age of 30. Mike is 3 years younger than twice Jasmines age. How old is Mike?

Mike is 19.

If you turn the question into an equation it turns to:

J x 2 - 3 = M

So since you don't know Jasmine's age you would use guess and check. 8,9, and 10 didn't work but when you put in 11:

11 x 2 - 3 = M

22 - 3 = M

19 = M

And to check your work

J + M has to equal 30 so,

11 + 19 = 30

30 = 30