改一改 ok?

( 1 ) 1 - 20% is very wrong as the Q asks for an increase but not a decrease.
48×(1-20%) means 48 is decreased by 20%.
Corrections:

Let the original number be x.
x ( 1 + 20% ) = 48
x = 48 / ( 1 + 20% )
x = 40
( 2 ) The calculation B = 110×(1-10%) means B is 10% less than A.
Then the % of A greater than B: { ( 110 - 99 ) / 99 } x 100% = 11.1% ( cor. to 3 s.f. )
This contradicts with the statement A is 10% greater than B.
Corrections:
A = B ( 1 + 10% )
A = 1.1B
B = A / 1.1
B = 110 / 1.1 = 100

1The number = 48/(1+20%)
= 40
2 B = 110/(1+10%)
= 100