STUDY GUIDE FOR MATH SECTION OF PSAT / NMSQT (These are the 20 most missed problems from previous years) 1) If 5n = k, where n is a positive integer, which of the following could be the value of k? (A) 1 2) (B) 10 (E) 350 (C) 16 (D) 24 (E) 32 (C) n-1 (D) n-3 (E) n+1 If x+ y+ z = 7 and 3x+3y = 12, what is the value of z? (A) 3 5) (D) 100 Sarah is 4 years younger than David. If n represents David’s age now, what will Sarah’s age be in 5 years in terms of n? (A) n+9 (B) n+5 4) (C) 125 Each time Jasmine counted her blocks by either 3’s or 5’s she had one left over. But when she counted them by 8’s, she had none left over. What is the least number of blocks she could have had? (A) 5 3) (B) 8 (B) 5 (C) 7 (D) 9 (E) 11 If the area of each face of a cube is 81sq. inches, what is the total length, in inches, of all the edges of the cube? (A) 54 (B) 64 (C) 108 (D) 120 (E) 280 6) Food X% Tuition 35% Books 12% Housing 30% Total cost of one year of college at Public University in TN = $9800 According to the graph, what percent of the total cost is food? (A) 20% (B) 23% (C) 13% 7) (B) 6 (C) 8 (D) -20 (E) -32 If (x+ y) 2 - (x- y) 2 = 140 and x and y are positive integers, which of the following could be a value of x+ y ? (A) 12 9) (E) 18% If |x+6| <12, which of the following could be a value of x? (A) 4 8) (D) 33% (B) 14 (C) 16 (D) 18 (E) 20 In the xy-plane, the line y = ax + 8 is perpendicular to the line 4x + 5y = 6. What is the value of a ? (A) -5 (B) – 4/5 (C) 5/4 (D) 6/5 (E) -6/5 10) An empty tank has a capacity of 20 gallons. A pump can deliver c gallons of gas every d seconds. In terms of c and d, how many seconds will it take this pump to fill the tank? (A) 20d/c (B) cd/20 (C) c/(20d) (D) 20c/d (E) 20cd 11) On the number line above, the letters represent consecutive integers. If a + g = 16, what is the value of d? (A) 5 (B) 6 (C) 7 (D) 8 (E)9 12) Equal numbers of cards that are marked either with a, b, or c are placed in a box. If one card is drawn at random from the box, what is the probability that it will be marked either b or c? (A) 1/9 (B) 1/3 (C) 1/2 (D) 2/3 (E) 4/9 13) The lengths of two sides of a triangle are 9 and 16, respectively. What is one possible length of the third side? 14) 20 gorps = 1 shaz 100 dinks = 1 shaz According to the equations above, how many dinks equal 50 gorps? 15) If ac = 20 and 4abc = 20, what is the value of 3b ? 16) Jennie has 12 large cookies and Max has 20 small cookies. They will trade one of Jennie’s large cookies for 2 of Max’s small cookies. After how many trades will Jennie and Max have an equal number of cookies? 17) Hexagon ABCDEF is a regular polygon. If the measure of <CAB is x◦ , what is the value of x? 18) If the average (arithmetic mean) of a, b, c, and d is 36, what is the average of 2a-4b, c+7-a, 4b+d, and b+13? 19) 12, 5, 7, 2, … In the sequence above, the first term is 12, the second term is 5, and each term after the second term is the nonnegative difference between the two previous terms. If the nth term is the first term of the sequence that is equal to zero, what is the value of n? 20) If x 6 = 2460 and x4 y = 12, what is the value of x 2 y?