SAT Subject Test Mathematics Level 1

As  usual   with    averages    questions,  the key is  to  use the sum.    The sum of

the 8   males’  scores  is

The sum of  the x females’  scores  is

The sum of  all the scores  is  the class   average (90)    times   the total   number

of  people  (8  males   and x   females)

Now set the sum of  the male    sum and the female  sum equal   to  the class

sum and solve   for x:

7 . E
To get the average speed, you need the total distance and the total time.
Whatever you call the distance, it will drop out eventually, so you can call
it whatever you want—a letter, an expression, a number. You might as
well make it something easy to work with. The question stem speaks of
“one-third” and “two-thirds” the distance, so it would be easiest to pick a
total distance like 3d kilometers. (Another good total distance you might