tailieunhanh - Sat - MC Grawhill part 43

Tham khảo tài liệu 'sat - mc grawhill part 43', ngoại ngữ, ngữ pháp tiếng anh phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 410 McGRAW-HILL S SAT Answer Key I Sequences Concept Review I 1. A sequence is simply a list of numbers each of which is called a term. 2. If the sequence repeats every six terms you can find the 115th term by finding the remainder when 115 is divided by 6. Since 115 6 equals 19 with a remainder of 1 the 115th term will be the same as the first term. 3. Begin by finding the sum of the repeating pattern. Next determine how many times the pattern occurs in the first 32 terms 32 4 8 times. Then multiply the sum of the pattern by 8 to obtain the sum. 4. Count the number of negative terms in each repetition of the pattern then find how many times the pattern repeats in the first 36 terms. Since 36 5 7 with a remainder of 1 the pattern repeats 7 times and is 1 term into the eighth repetition. Multiply the number of negative terms per repetition by 7 and if the first term of the sequence is negative add 1 to the total. 5. This is a geometric sequence. Each term is the previous one times 3 1 X 3 3 3 X 3 9 etc. . The first term of the sequence is 3 2 and the 30th term is 3 - 2 X 329 327. 6. The first term is 4. Second 4 2 8 16. Third 16 2 8 40. Fourth 40 2 8 88. Fifth 88 2 8 184. Sixth 184 2 8 376. 7. The pattern repeats every five terms and each repetition contains two vowels. Since 143 5 28 with a remainder of 3 the first 143 letters contain 28 X 2 56 vowels plus the one vowel in the first three letters of the word SCORE for a total of 56 1 57. 8. Work backwards x was found by subtracting 3 from the second term and dividing by 2. Therefore multiply x by 2 and add 3 to get the second term 2x 3. Repeat to find the first term 2 2x 3 3 4x 9. 9. The integers 1 through 9 represent the first 9 digits and 10 through 19 represent the next 20 digits. Each integer thereafter contains 2 digits. 26 represents the 42nd and 43rd digits so 2 is the 44th digit. SAT Practice 1 1. D The first term of the sequence is x. The second term is 2 x 3 2x 3. The third term is 2 2x 3 3 4x 6 3 4x 9. .