# Mathematics Puzzle : 1+4 = 5 , 2+5 = 12 , 3+6 =21 , 8+11 = ?

## 2 thoughts on “Mathematics Puzzle : 1+4 = 5 , 2+5 = 12 , 3+6 =21 , 8+11 = ?”

1. blueC says:

This has another answer that fits better. As base addition is implied with 1+4 = 5, the following sets don’t fit to that, so the idea is to use the numbers there to make an equation that fits. I would say it makes more sense that the common equation would be First number X times second number (Y+1).
This fits all shown sets. First equation 1*(4+1) = 5, second: 2*(5+1)=12, third: 3*(6+1)=21
which would make the last one 8*(11+1)=96
This variant would actually make more logical sense with the setup showing that the addition symbol is a trick, but that you don’t need to use the other variables from previous equations, just the concepts.

1. blueC says:

You could fix the initial equation to fit your premise by just rotating the first set.
If the first one read 4+1= 5 instead of 1+4 = 5, then everything would match your current answer and not the one i’ve suggested. As with my suggestion it would become 4*(1+1)= 8.