3+4 = 7. 19/7 = 2.71
5+6 = 11. 41/11 = 3.73
1+3 = 4. ?/4 = 4.75 <--- Following the pattern of +1.02 (2.71+1.02=3.73, therefore 3.73+1.02=4.75
We still need (?) ... ?/4=4.75 we can re-write this as 4(4.75)=?
4(4.75) = 19 (4x4=16, 4x0.75=3, 16+3=19)
Therefore, 1+3=19.
