Question

A tectonic plate near Niihau, an island in Hawaii, grows at an average rate of 11 cm/year. If the rate of plate expansion doubles, how many more centimeters will the plate grow in 3 years, compared to the present rate?

A) 30 cm more

B) 33 cm more

C) 66 cm more

D) 122 cm more

Answer 1

C, 66

Step-by-step explanation:

11*2 is 22 and 22*3 is 66

Answer 2

Answer: Option C: 66 cm more

Explanation: We know that the actual rate is 11 cm per year, if this rate is doubled, then the new rate is 11*2 cm per year = 22cm per year.

Now, if in one year the plate grows 22 cm, then in 3 years the plate will grow 3 times 22 cm, this is:

22cm*3 = 66cm

Then the right answer is C, 66 cm more.