Explanation:
Let the number to be found be x
a).
68 is what percent of 80 is written as

Multiply both sides by 100
We have
80x = 6800
Divide both sides by 80
we have the answer as
x = 85
Therefore the percentage is 85%
b).
Let the number be x
88.83 is 423% of what is written as

Multiply through by 100
We have
423x = 8883
Divide both sides by 423
We have the answer as
x = 21
The number is 21
c).
Let the number be x
36.8% of what number is 28.52 is written as

Multiply through 100
We have
36.8x = 2852
Divide both sides by 36.8
We have the answer as
x = 77.5
The number is 77.5
d).
What number is 95% of 40 is written as

We have the final answer as
38
Hope this helps you