The students in Ms. Winter's class were tracking the movement of some birds in the school's garden. The mother bird flew over to the bird feeder, stopped for some seeds, and then flew back to her nest. How long did the bird's trip take?
A. 5 sec
B. 10 sec
C. 12.5 sec
D. 15.5 sec

Scott harris can invest $7,000 in a 1-year cd that earns interest at an annual rate of 4 percent compounded monthly. the amount per $1.00 is 1.040742. he can also invest $7,000 in a 1-year cd at annual rate of 4 percent compounded quarterly. the amount per $1.00 is 1.040604. what is the difference in the amount of interest earned for each investment? a) $0.96 b) $0.81 c) $0.87 d) $0.88

In a two-digit number the units' digit is 7 more than the tens' digit. the number with digits reversed is three times as large as the sum of the original number and the two digits. find the number.

In the diagram, ab is tangent to c, ab = 4 inches, and ad = 2 inches. find the radius of the circle.