Home->ACT Math

Which one of the following expresses the number of meters that a contestant must travel in a 5-lap race around a circular track with a radius of R meters?

(A)5R

(B) 5πR

(C) 5πR²

(D) 6R

(E) 10πR

Given that i²= –1, what is the value of (4 + 2i)(4 – 2i)?

(A) 12(B) 20(C) 16 – 4i(D) 4 + 16i(E) 12 – 16i

Correct Answer: B

The diagonal of a square quilt is 4 feet long. What is the area of the quilt in square feet?

(F) 16

(G) 16

(H) 4

(J) 4

(K)

Correct Answer: G

Isosceles triangle T₁ has a base of 12 meters and a height of 20 meters. The vertices of a second triangle T₂ are the midpoints of the sides of T₁. The vertices of a third triangle, T₃, are the midpoints of the sides of T₂. Assume the process continues indefinitely, with the vertices of T_k+1 being the midpoints of the sides of T_k for every positive integer k. What is the sum of the areas, in square meters, of T₁, T₂, T₃, …?

(F) 30 (G) 40 (H) 120 (J) 144 (K) 160

Correct Answer: K