2 questions from GRE General Test 10th Ed

[giddy]

On a turntable, a record of radius 6 inches is rotating at the rate of 45 revolutions per minute.

Col A

The number of inches traveled per minute by a point on the circumference of the record

Col B

The number of inches traveled per minute by a point on the record 5 inches from the center of the record

SPOILER: A

In a history class that consisted of 30 students, the number of seniors was 3 more than twice the number of juniors, and 3/10 of the students were neither juniors nor seniors.

Col A

The number of juniors in the class

Col B

6

SPOILER: C

Please explain. Thank you.

[prithibi]

1. answer:A
plz tell me m i right or wrong.
i just find out the circumference of the circle.

[prithibi]

2. answer: C

3/10 students are neither junior or senior i. e. 9
again 30-9=21 students are either junior or senior.
let number of junior =x
so number of seniors= 2*x+3
now, x+2*x+3=21
and x= 6

got it?

[grexam]

1) the inches travelled by the point on 6inches radius record is 6^2*45
and another point 5 inches radius is 5^2*45
hence the first point travels more so its A
even I feel its A correct if wrong

2)total students=30
seniors=s=2j+3
juniors=j
none=(3/10)*30=9
s+j+9=30
3j+12=30
j=6
Hence C


Please correct first one if wrong I too feel A is the answer

[Goldust]

For question 1, consider the simple fact that two points on the same radius, one on the circumference and one inside the circle travel with the same angular velocity (Don't worry if you don't know the term). Both move by equal angles in equal amounts of time. Obviously, with a greater radius, the arc length is greater. Hence, the answer is intuitively A. Even if the points are on different radii, the angles covered in equal times would be equal.

[sandipank]

Hello
Can you please tell me what is this GRE General Test 10th edition?
is it Barrons or Kaplans???
PLease reply to sandipank@gmail.com
Thanks in advance

[Goldust]

The GRE 10th edition is like a watered-down version of Big Book. It is published by ETS.