﻿ ﻿EXERCISES - Sequences and Series - Numbers and Operations - REVIEW OF MAJOR TOPICS - SAT SUBJECT TEST MATH LEVEL 2

## PART 2 ## REVIEW OF MAJOR TOPICS ## Numbers and Operations

### 3.4 Sequences and Series ### EXERCISES

1. If a1 = 3 and an = n + an–1, the sum of the first five terms is

(A) 17

(B) 30

(C) 42

(D) 45

(E) 68

2. If a1 = 5 and find a3.

(A) 2.623

(B) 2.635

(C) 2.673

(D) 2.799

(E) 3.323

3. If the repeating decimal is written as a fraction in lowest terms, the sum of the numerator and denominator is

(A) 16

(B) 47

(C) 245

(D) 334

(E) 1237

4. The first three terms of a geometric sequence are The fourth term is

(A) (B) (C) (D) (E) 5. By how much does the arithmetic mean between 1 and 25 exceed the positive geometric mean between 1 and 25?

(A) 5

(C) 8

(D) 12.9

(E) 18

6. In a geometric series and . What is r ?

(A) (B) (C) (D) (E) 1. (D) a2 = 5, a3 = 8, a4 = 12, a5 = 17. Therefore, S5 = 45

2. * (D) Press 5 ENTER into your graphing calculator. Then enter and press ENTER twice more to get a3.

3. * (C) The decimal = 0.2 + (0.037 + 0.00037 + 0.0000037 + · · ·), which is 0.2 + an infinite geometric series with a common ratio of 0.01. The sum of the numerator and the denominator is 245.

4. (D) Terms are 31/4, 31/8, 1. Common ratio = 3–1/8. Therefore, the fourth term is 1 · 3–1/8 = 3–1/8 or 5. (C) Arithmetic mean Geometric mean The difference is 8.

6 (D) Therefore, ﻿