Answer:
a. 19 Questions
b. No, Collins grade was 81%, or B-minus :(
Explanation:
There are 21 questions in total on the test. Collin wants a 90 percent at least. If you multiply 21 by 90 percent (as below), you will get 18.9
Of course, you can't get 18.9 questions right (unless you're teacher gives .9 extra points lol, So we need to round UP to a whole number (don't round down because it'll give you a number lower than what 90 percent would equate to.
And, Collin got 17 questions right. That's equivalent to 81 percent of 21 (as below).
This rounds to about 81%, meaning Collin did not reach his goal :(. Oh well, he'll just have to try harder next time!
Have a nice day, fam.