Math 7-2

The value of all of the quarters and dimes in a parking meter is $18. There are twice as many quarters as dimes. What is the total number of dimes in the parking meter?

• 40

• 20

• 60

• 80

A ball is dropped from a height of 12 m and it rebounds 1/2 of the distance it falls. If it continues to fall and rebound in this way, how far will it travel before coming to rest?

• 36 m

• 30 m

• 48 m

• 60 m

At t = 0, a particle starts at rest and moves along a line in such a way that at time t its acceleration is 24t² feet per second per second. Through how many feet does the particle move during the first 2 seconds?

• 32

• 48

• 64

• 96

If a trip takes 4 hours at an average speed of 55 miles per hour, which of the following is closest to the time the same trip would take at an average speed of 65 miles per hour?

• 3.0 hours

• 3.4 hours

• 3.8 hours

• 4.1 hours

A laboratory has a 75-gram sample of radioactive material. The half-life of the material is 10 days. What is the mass of the laboratory’s sample remaining after 30 days?

• 9.375 grams

• 11.25 grams

• 12.5 grams

• 22.5 grams

The unit normal to the plane 2x + y + 2z = 6 can be expressed in the vector form as

• î + 3ĵ + 2k̂

• (2/3) î + (1/3) ĵ + (2/3) k̂

• (1/3) î + (1/2) ĵ + (1/3) k̂

• i2/3+ j1/3 + k2/3

d/dx (ln e²x) =

• e²x

• 2/e²x

• 2x

• 2

Determine where, if anywhere, the tangent line to f(x) = x³ - 5x² + x is parallel to the line y = 4x + 23.

• x = 3.61

• x = 3.23

• x = 3

• x = 3.43

Which of the following is equivalent to the expression below? (x² - 3x + 1) - (4x - 2)

• x² - 7x + 3

• -3x² - 3x

• -3x² - 3x + 3

• x² + 12x + 2

For what value of k will x + k/x have a relative maximum at x = -2?

• -4

• -2

• 2

• 4