Home->ACT Math

A function f is defined by f(x,y) = x - (xy - y). What is the value of f(8,6)?

(A)-46

(B) -34

(C) 46

(D) 50

(E) 62

Find two arithmetic means between 11 and 26 such that the difference between consecutive numbers is the same: 11,________ ,________, 26

（A）14, 18 （B） 15, 20 （C） 16, 21 （D） 17, 23 （E） 18, 24

Correct Answer: C

A certain 18-quart stockpot is filled completely with water and exposed to a heat source so that the water boils away at a constant rate. The water remaining in the stockpot can be approximated by the following equation: y = 18 - 0.2x, where x is the number of minutes that the pot has been heated for 0 ≤ x ≤ 90, and y is the number of quarts remaining in the pot. According to this equation, which of the following statements is true about this stockpot?

(F) After 0.2 minutes, 1 quart of water has boiled away. (G) After 1 minute, 0.2 quarts of water have boiled away. (H) After 18 minutes, 0.2 quarts of water have boiled away. (J) After 18 minutes, 1 quart of water has boiled away. (K) After 36 minutes, 18 quarts of water have boiled away.

Correct Answer: G

What is the equation for a line that intersects the origin and is perpendicular to 2x– 4y= 13?

(A) y= –2(B) y= 2x(C) y= –2x(D) (E)

Correct Answer: C