Math

Five times the difference of twice a number and three, decreased by the sum of this number and eight, equals thirteen.

related riddles

1+1+2+2+3+3+4+4+5+5

The combined age of Jack and John is 49. Jack is twice as old, as John was when Jack was as old as John is now. How old are the brothers?

20+20+20=60. How can you make 60 again by using the same number 3 times, but it can’t be 20?