To solve part a, do the following.
49.84-44.50=5.34
5.34/44.50=x/100
after solving the proportion, x would be equal to 12.
To solve part b, do the following.
50+12=62
To solve part c, do the following.
The amount of the tip is:
x/57.50=62/100
which is 35.65
The total bill is:
35.65+57.50=93.15