If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

# GMAT: Math 21

110-114, pgs. 166-167. Created by Sal Khan.

## Want to join the conversation?

• hey I got this test question finding it hard
a shop has a special offer
reduction of 10% when your bill is between £50 and£100
reduction of 20% when your bill is more than £100
before the reductions, mary bill is £96 and Richard bill is£ 108
after reduction who paid more
it is quite ok q
but not sure bout it
• In problem # 114, the question is "Which of the following is the product of two integers whose sum is 11?" I don't understand why the answer is -42 and not any other sum of integers that equal 11. For example, I could just as easily say that 18 is the answer (2 x 9), or 24 is the answer (3 x 8) or 30 is the answer (6 x 5). Why -14 and 3?
• If the sum of the two numbers equal 11, the two numbers have to be odd and even. Your response is correct, but the answer choices in the book are A. -42, B. -28 C. 12 D.26. E. 32. Since you seem like you know the multiplication table, you can mentally see which choices would work. For example -13+-2 = -26, will give you an idea on where to start.
You can then rule out -28 because -7+4, -14+2, and 28+1 don't equal 11. This leaves you with choice A and you can double check your answer by factoring -42 out -6*7= 2*-3*7=14*-3=-42.
• 12th edition review Q: 106; When positive integer X is divided by positive integer Y the remainder is 9. If X/Y=96,12 what is the value of y? A)96 B)75 C)48 D)25 E)12
• Solution:
X/Y gives remainder 9 that means X = kY + 9 => X/Y= k + 9/Y
Now, X/Y = 96.12 => dividing X by Y fetches 96 and the remaining 0.12 is the remainder divided by Y in decimal
=> 9/Y = 0.12
=> 9 = 0.12 * Y
=> Y = 9/0.12
=> Y = 900/12 = 75

Ans: B
• #113 theoretically -0.3squared with -0.3 out of parenthesis, the answer should be a negative, but (-0.3)squared should be a positive. I get the math however for the GMAT I anticipate this confusing me - when should I assume the coefficient is in a parenthesis (such as the approach you used on this problem) and when should I assume it is not? Thanks for the help.
(1 vote)
• i would appreciate if someone can just post the link for the list of these questions solved above in the video. Thank You.