B) David and Andrew are traveling to a Mathematics conference. David travels 110 miles in the same time that Andrew travels 140 miles. Andrew travels 15 miles per hour faster than David. Find the average rate of each person.

David's average speed is 55 mph and Andrew's average speed is 70 mph

Step-by-step explanation:

Let David's speed be s.

Average speed is given as:

speed = distance / time

They both spent the same time, t.

David's speed is:

s = 110 / t

=> t = 110 / s

Andrew travels 15 mph faster than David.

Andrew's speed is:

(15 + s) = 140 / t

=> t = 140 / (15 + s)

Therefore, since they spent the same time:

110 / s = 140 / (15 + s)

Cross multiply:

110(15 + s) = 140s

1650 + 110s = 140s

1650 = 140s - 110s

30s = 1650

s = 1650 / 30

s = 55 mph

Andrew's speed is:

15 + 55 = 70 mph

Therefore, David's average speed is 55 mph and Andrew's average speed is 70 mph.

answer: option a.

step-by-step explanation:

you know that the quadrilateral opqr ( a four sided figure) is inscribed in circle. this means that all its vertices are on the circle.

then, by definition, the opposite angles of the quadrilateral are supplementary, this means that the sum of their measures is 180 degrees.

you can observe in the figure that the angles ∠opq   and the angle ∠orq   are opposite, therefore:

then, can be used to d to calculate the measure of ∠opq