Answer:
a. 19 Questions
b. No, Collins grade was 81%, or B-minus :(
Step-by-step 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
[tex]21 * .9\\=18.9[/tex]
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).
[tex]17 / 21\\=.8095[/tex]
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.
