GRE数学1【荐】.ppt

Decimals and Fractions GRE Quantitative Section - denominator, numerator - proper fraction, improper fraction - simple fraction, mixed number - reciprocals Quantity A Quantity B The least common denominator of 15 1/2, 1/3, and 1/4 Ratios, Proportions and Percents * Judy is 3 times as old as Sam. * There are twice as many chocolate cookies as vanilla in the cookie jar. * My brother earns $5 for each $6 I earn. GRE Quantitative Section * Chocolate cookies are twice as many as vanilla in the cookie jar. 1. If the selling price of model B is 60% more than the selling price of model A, what percent of the total sales do the sales of model A represent? (A)25% (B)36% (C)38% (D)40% (E)42% GRE Quantitative Section 2. If A, B, C, and D lie on the same straight line, and if AC=2CD=3BD, what is the value of the ratio BC:CD? (A)1:6 (B)1:3 (C)1:2 (D)5:3 (E)It cannot be determined from the information given. Sequences progressions 3，7，11，15，… 7，21，63，189，… GRE Quantitative Section Arithmetic Sequence Geometric Sequence progression (Series) 1. What is the difference between the sum of all positive even integers less than 102 and the sum of all positive odd integers less than 102? (A) 0 (B) 1 (C) 50 (D) 51 (E)101 2.In a certain sequence the difference between any two consecutive terms is 5. If the 20th term is 63, what is the 2nd term? (A)-32 (B)-27 (C)-22 (D)32 (E)37 GRE Quantitative Section 3. A sequence of numbers begins 1,1,1,2,2,3 and then repeats this pattern of six numbers forever. What is the sum of the 135th, 136th, and 137th numbers in the sequence? (A) 3 (B) 4 (C) 5 (D) 6 (E) 7 GRE Quantitative Section 4. The first term of a sequence is 1. Starting with the second term, each term is 1 less than 3 times the preceding term. Quantity A Quantity B The smallest number greater than 100 in