You can tabulate down the given data from question.

Speed in Original Design 
Speed in New Design 
# of Operations given(2:3) 
Floating Point (FP) operations 
100 
120 
2x 
Fixed Point (XP) operations 
200 
220 
3x 
Here, Speed = #operations per unit time (Just like speed = distance/time)
Took 100,200 for FP and XP for easy understanding.
Say 5x is total number of operations, in which 2x FP and 3x XP operations
Speed up = $\frac{Time in Original Design}{Time in New Design}$
=>$\frac{2x/100 + 3x/200}{2x/120 + 3x/220}$ (Since we know time = #operations/speed)
we get Speed up = 1.155, So Option (A)
Hope this solution was easy to understand