Which is different?
find "both" answers.

*what number is 20% of 55?
*55 is 20% of what number?
*20% of 55 is what number?
*0.2×55 is what number?

Lets group equivalent questions, and answer them afterwards:

*What number is 20% of 55?
*20% of 55 is what number?
*0.2×55 is what number?
These questions are equivalent. We can calculate the 20% of 55 by multiplying them, take into account that 20% = 20 out of 100 = 20/100, so we have
(20%)(55)
= (20/100)(55)
= (1/5)(55)
= 11
hence, 11 is the 20% of 55
It is also equivalent to 0.2x55 because 20% = 20/100 = 2/10 = 0.2, hence we just need to multiply.

*55 is 20% of what number?
we need to find a number x such that when it is multiplied by 20% give us as result 55, take into account that 20% = 20 out of hundred = 20/100
= 1/5, so we have
(1/5)x = 55
solving for x:
x = 5*55
x = 275
so, 55 is the 20% of 275