Regina scored 84% on a test. she answered 63 items correctly. how many items did regina answer incorrectly?

STEP 1:
Find total number of questions on the test. The percent (84%) is out of 100%. So set up a proportion. 84% out of 100% is 63 out of x (total number of questions on the test).

x= total # questions on test

63/x= 84%/100%
cross multiply
(63*100)= (x*84)
6300= 84x
divide both sides by 84
75= x (total # on test)

STEP 2:
Subtract number correct from total number of questions to equal number incorrect.

x= number incorrect on test

x= 75 - 63
x= 12 incorrect answers

ANSWER: 12 incorrect answers

Hope this helps! :)