sthamina

If k is an even integer and p and r are odd integers, which of the following CANNOT be an integer? (A) r/k (B) k/p © p/r (D) kp/r (E) kr/p Anyone has a good approach for this question?

Thank you vgp. It's the simple approach I was looking for.

How many liters of pure alcohol must be added to a 100-liter solution that is 20 percent alcohol in order to produce a solution that is 25 percent alcohol? A. 7/2 B. 5 C. 20/3 D. 8 E. 39/4 What is the fastest approach for this question? Thank you OA:

If x is different from 0, then (squareroot(x)^2)/x = A) -1 B) 0 C) 1 D) x E) |x|/x Tricky?! OA:

If d is the standard deviation of x, y, z what is the standard deviation of x+5, y+5, z+5? A) d B) 3d C) 15d D) d + 5 E) d + 15 Any standard deviation rule I am not aware of? OA:

Circular gear P & Q start rotating at the same time at constant speeds. Gear P makes 10 revolutions per minute, and gear Q makes 40 recolutions per minute. How many secs after the gears start rotating will gear Q have exactly 6 more revolutions than gear P? (A) 6 (B) 8 © 10 (D) 12 (E) 15 I tried to use the work/rate equation, but don't seem to know how to even approach this question.Thank you. OA:

If wx=y, what is the value of xy? (1) w(x)^2= 16 (2) y=16 OA:

Thank you guys! These are all great approaches that I needed to think about slope questions. they're many of these type of questions I couldn't do before.

The y-intercept of a line l is 4. If the slope of l is negative, which of the following could be the x-intercept of l? I) -1 II) 0 III) 6 A) I only B) II only C) III only D) I & II E) I & III Please explain your approach. OA:

Thank you very much! I got it!

The Issue it that you changed the initial equation from k^2 = 2.601 * 10^9 to k^2 = 5.1^2 *10^8. I really don't see how you did that. Sorry for being slow here.

venkat, how did you derive from 2) that k is 5.1*10^4?

Great! I get it now. Thanks again.

Thank you venkat. I finally saw how to approach this. I let r^3=972 intimidate me. I didn't see that 972= 9*9*9 which makes r=9 Then, plug in 9 into the surface area equation. Thank you,

My mistake was that I substituted with y with 5, by plugging in the answer choice and I used 5 as the answer, instead of 2. |-2| = 2. Thanks for your clarification