1. 19 is what percent of 40

a. 19=n x 40;47.5%
b. 40=19 x n;2.1%
c. 40=19 x n;40.4%
d. 19=n x 40;52.3%

is it a?

2.64 is 80% of what?

a.64 x n=80; 0.8
b.0.64 x n=80; 125
c.60= 0.80 x n;80
d.80=64 x n;1.3

is it c?

3 answers

Yes for both. Good job.
yes they are both correct the way you have them.
1a is correct.

0.8*n = 64

n = 80

You wrote the problem wrong in 2c. 60 should be 64