9. What is the value of n in 9 : 4 = n : 28?

32
48
54
63

16. If 10% of a number is 100, what is the number?

100
1,000
10,000
100,000

17. What percent of 200 is 10?

5%
10%
15%
25%

18. In the proportion 4/6 = 6/N , what is the value of n?

9
10
11
12

20. Change 0.78 to %.

0.78%
7.8%
78%
780%

21. In a class of 40 students, 70% are boys. How many are boys in the class?

15
18
20
28​