Home->ACT Math

What is the greatest common factor of 42, 126, and 210 ?

(A)2

(B)6

(C)14

(D)21

(E)42

Below is the graph that a specialty automobile manufacturer uses to plot the speed tests done on his new cars. The speed is recorded in units of and is conducted for a period of 9 seconds. A certain order of 3 of the following 6 actions describes the results of the speed test depicted in the graph below. Which order is it?

I. Constant speed for 1 second

II. Constant speed for 3 seconds

III. Speed increase for 4 seconds

IV. Speed increase for 9 seconds

V. Speed decrease for 2 seconds

VI. Speed decrease for 7 seconds

(F) IV, II, VI (G) III, II, V (H) I, III, V (J) III, I, VI (K) V, I, II

Correct Answer: G

For the imaginary number i, which of the following is a possible value of iⁿ if n is an integer less than 5?

(A) 0 (B) -1 (C) -2 (D) -3 (E) -4

Correct Answer: B

In the figure below, M is on and O is on . and are parallel. The dimensions given are in feet. What is the length, in feet, of ?

（A）39 （B） 91 （C） 105 （D） 273 （E） 294

Correct Answer: B