SAT math - help please

Test Preparation SAT Preparation
1

I’ve looked up explanations but they are not thorough enough…

  1. If 75 percent of m is equal to k percent of 25, where k > 0, what is the value of m/k

A) 3/16
CORRECT ANSWER B) 1/3
C) 3/4
D) 3
E 16/3

  1. A telephone company charges x cents for the first minute of a call and charges for any additional time at the rate of y cents per minute. If a certain call costs $5.55 and lasts longer than 1 minute, which of the following expressions represents the length of the call, in minutes?

A) (555-x) / y
B) (555±y)/y
CORRECT ANSWER: C) (555-x+y)/y
D) (555-x-y)/y
E) (555) / (x + y)

2

1 -

I would just plug in numbers. There is most likely an algebraic way of doing this, but I think plugging in numbers is easiest.

If m=100, the equation will be 75=0.25k (75% of 100 is 75).
You multiply 75 by 4 to get k. That = 300. So k=300. Then it asks m/k.
100/300 = 1/3.
1/3 is your answer

Plugging in numbers works often on the SAT.

3

There is another thread on this with other options as well.