Exercise 34 Page 361

Remember, you can use the following formula to find p % of the number n. n*p/100

Finding the Distance at Speed 70 miles per hour

Let's start with finding the distance they covered at a speed of 70 miles per hour. According to the information, this is 65 % of 300 miles. 300*65/100=195 They covered 195 miles at a speed of 70 miles per hour.

Finding the Distance at Speed 35 miles per hour or less

Since they covered 195 miles at a speed of 70 miles per hour, the rest of the trip is 300-195=105 miles long. According to the information, Mrs. Ross did not drive faster that 35 miles per hour for 20 % of this remaining distance. 105*20/100=21 They covered 21 miles at a speed of 35 miles per hour or less.

Finding the Distance at Speed between 35 and 70 miles per hour

Let x be the distance Mrs. Ross drove at a speed between 35 and 70 miles per hour. Since she did not go over 70 miles per hour, we add this distance to the sum of 195 miles. She covered this at 70 miles per hour, and 21 miles she covered not faster than 35 miles per hour, so we get 300 miles, the total length of the trip.

The Ross family traveled 84 miles at a speed between 35 and 70 miles per hour. The correct choice is B.