1.What is the value of 2(0(19))+((20)1)9?(A) 0 (B) 1 (C) 2 (D) 3 (E) 4译文:2(0(19))+((20)1)9的值是多少?解原式=20+19=2,故(C)正确.2. What is the hundreds digit of (20!-15!)?(A) 0 (B) 1 (C...1.What is the value of 2(0(19))+((20)1)9?(A) 0 (B) 1 (C) 2 (D) 3 (E) 4译文:2(0(19))+((20)1)9的值是多少?解原式=20+19=2,故(C)正确.2. What is the hundreds digit of (20!-15!)?(A) 0 (B) 1 (C) 2 (D) 4 (E) 5译文:(20!-15!)的百位数是多少?解20!的标准分解式中含有[20/5]=4个5, 15!的标准分解式中含有[15/5]=3个5,即它们的最后三位数均为0,从而(20!-15!)的百位数是0,故(A)正确.3. Ana and Bonita were born on the same date in different years, n years apart. Last year Ana was 5 times as old as Bonita.This year Ana’s age is the square of Bonita’s age. What is n?(A) 3 (B) 5 (C) 9 (D) 12 (E)展开更多
文摘1.What is the value of 2(0(19))+((20)1)9?(A) 0 (B) 1 (C) 2 (D) 3 (E) 4译文:2(0(19))+((20)1)9的值是多少?解原式=20+19=2,故(C)正确.2. What is the hundreds digit of (20!-15!)?(A) 0 (B) 1 (C) 2 (D) 4 (E) 5译文:(20!-15!)的百位数是多少?解20!的标准分解式中含有[20/5]=4个5, 15!的标准分解式中含有[15/5]=3个5,即它们的最后三位数均为0,从而(20!-15!)的百位数是0,故(A)正确.3. Ana and Bonita were born on the same date in different years, n years apart. Last year Ana was 5 times as old as Bonita.This year Ana’s age is the square of Bonita’s age. What is n?(A) 3 (B) 5 (C) 9 (D) 12 (E)