Well, for the first question, just multiply 67 by .71 and you'll get your answer, 47.57%
For question 2, just divide 205 by 41, which is 5, and we know that 1/5 in decimal form is .2, and .2 is equivalent to 20%
Question 3, we know that 75% is 3/4 of 100%, so all we have to do is divide 15 by 3 to get 5, then multiply 5 by 4 to get the total students in the class, 20.
For question 4, just divide 24 by 40 to get .6, which we know equals 60%