From 1 to 4, we need to jump 8 spaces to the right.

8 spaces = increase in value of 3
1 space = increase in value of 3/8

For A, the number is obtained by adding 4 spaces to 1.

4 spaces
= increase of 3/8 per space times 4
= increase of 3/2 (after simplification)
= increase of 1 1/2

So, the value of A
= 1 + 1 1/2
= 2 1/2

Similarly, for B, the number is obtained by adding 6 spaces to 1.

6 spaces
= increase of 3/8 per space times 6
= increase of 9/4 (after simplification)
= increase of 2 1/4

So, the value of B
= 1 + 2 1/4
= 3 1/4

So, the total value of A + B
= 2 1/2 + 3 1/4
= 2 2/4 + 3 1/4
= 5 3/4