John can read 72 pages per hour. At this rate, how many pages can he read in 72 minutes
Answer : B
Explanation:
Set up a proportion: 72 pages/1hr = 72 pages/60mins =xpages/72minutes 72 pages/60mins =xpages/72minutes Therefore 72 x 72 = 60x X = 5184/60 X = 86.4 (B)
A hospital has enough pills on hand to treat 10 patients for 14 days. How long will the pills last if there are 35 patients.
Answer : A
This is a rate problem. The more the patients, the less the days the drugs can last. So Patients is indirectly proportional to Days (Patients α 1/Days) Let P represent Pills Let D represent Days P α 1/D P = K/D ( Where K = constant) PD= K 10 x 14 = K K = 140 Using the equation PD = K For 35 patients, the pills will last for 35 x D = 140 D = 140/35 = 4 (A)
The price of a can of soup was increased by 20%. How many cans can be purchased for the amount of money that used to buy 300 cans?
Answer : C
Assume that a can of soup used to cost N1 and that it now costs N1.20 (by 20% increase). Then 300 cans of soup used to cost N 300. Therefore, how many cans can be bought for N300? N 300/1.20 = N 250 (C)
If 25 students took an exam and 4 of them failed, what percent of them passed?
If 4 students failed, then the other 25-4 = 21. 21 students passed, and 21/25 =0.84 84% (A)
Judy is now twice as old as Adam but 6 years ago she was 5 times as old as he was. How old is Judy now?
Represent Adam with A Represent Judy with J Judy now is twice as old as Adam J = 2A Six years ago J-6 = 5(A-6)
Therefore, J-6 = 5A – 30 J-6 = 5(J/2) – 30 Multiply through by 2 2(J-6) = 5J-60 2J-12 = 5J-60 -12+60 = 5J-60 48 = 3J J = 48/3 J = 16 (B)
