Home->ACT Math

For any positive two-digit integer x with tens digit t, units digit u, and t ≠ u, y is the two-digit integer formed when the digits of x are reversed. What is the greatest possible value of (y - x) when t is less than u?

(A)u - t

(B) ut - tu

(C) t² - 10tu + u²

(D) 9|u - t|

(E) Cannot be determined from the given information

Greg is making a triangular sail for a boat, shaped like a right triangle and shown below.

To determine how much trim to buy for the sail, Greg calculated the sail's perimeter. What is the sail's perimeter, in feet?

(A) 275 (B) 300 (C) 290 (D) 220 (E) 170

Correct Answer: B

Which of the following gives the equation for the circle in the standard (x,y) coordinate plane with a center at (4,-8) and a circumference of 10π square coordinate units?

(A) (x - 4)² + (y + 8)² = 25 (B) (x - 4)² + (y + 8)² = 100 (C) (x + 8)² + (y - 4)² = 25 (D) (x + 8)² - (y - 4)² = 100 (E) (x + 8)² + (y - 4)² = 100

Correct Answer: A

Which of the following equations represents the linear relation shown in the standard (x,y) coordinate plane below?

(A) y = -5x(B) y = -6x(C) y = -2x + 2(D) y = -5x + 6(E) y = -2x + 6

Correct Answer: D