Problem 57

Using the letters A,M,O,S,and U, we can form five-letter “words”. If these “words” are arranged in alphabetical order, then the “word” USAMO occupies position

(A) 112 (B) 113 (C) 114 (D) 115 (E) 116

ANSWER: D

Problem 56

Suppose July of year N has five Mondays. Which of the following must occur five times in the August of year N? (Note: Both months have 31 days)

(A) Monday (B) Tuesday (C) Wednesday (D) Thursday (E) Friday

ANSWER: D

Problem 55

The arithmetic mean of the nine numbers in the set {9,99,999,9999,…,999999999} is a 9-digit number M, all of whose digits are distinct. The number M does not contain the digit

(A) 0 (B) 2 (C) 4 (D) 6 (E) 8

ANSWER: A

Problem 54

Tina randomly selects two distinct numbers from the set {1,2,3,4,5}, and Sergio randomly selects a number from the set {1,2,…,10}. What is the probability that Sergio’s number is larger than the sum of the two numbers chosen by Tina ?

(A) 2/5 (B) 9/20 (C) 1/2 (D) 11/20 (E) 24/25

ANSWER: A

Problem 53

Points A,B,C, and D lie on a line, in that order, with AB=CD and BC=12. Point E is not on the line, and BE=CE=10. The perimeter of triangle AED is twice the perimeter of triangle BEC. Find AB.

(A) 15/2 (B) 8 (C) 17/2 (D) 9 (E) 19/2

ANSWER: D

Problem 52

A set of tiles numbered 1 through 100 is modified repeatedly by the following operation: remove all tiles numbered with a perfect square, and renumbered the remaining tiles consecutively starting with 1. How many times must the operation be performed to reduce the number of tiles in the set to one ?

(A) 10 (B) 11 (C) 18 (D) 19 (E) 20

ANSWER:C

Problem 50

A 3*3*3 cube is made of 27 normal dice. Each die’s opposite sides sum to 7. What is the smallest possible sum of all of the values visible on the 6 faces of the large cube ?

(A) 60 (B) 72 (C) 84 (D) 90 (E) 96

ANSWER: D

Problem 49

Sarah pours 4 ounces of coffee into a cup that can hold 8 ounces. Then she pours 4 ounces of cream into a second cup that can also hold 8 ounces. She then pours half of the contents of the first cup into the second cup, completely mixes the contents of the second cup, then pours half of the contents of the second cup back into the first cup. What fraction of the contents in the first cup is cream ?

(A) 1/4 (B) 1/3 (C) 3/8 (D) 2/5 (E) 1/2

ANSWER: D

Problem 48

Mr. Earl leaves home every day at 8:00 AM to go to work. If he drives at an average speed of 40 miles per hour, he will be late by 3 minutes. If he drives at an average speed of 60 miles per hour, he will be early by 3 minutes. How many miles per hour does Mr.Earl need to drive to get to work exactly on time ?

(A) 45 (B) 48 (C) 50 (D) 55 (E) 58

ANSWER: B