GMAT Review Questions and Answers Coordinate plane quadrants ✅left to right = II, I, III, IV 45/45/90 Triangle ✅x, x, x√2 30-60-90 triangle ✅x, x√3, 2x Area of Trapezoid ✅(b1 + b2)/2 * h Inscribed angle ✅length of outside = degree of inscribed or 2x degree of center cylinder volume ✅πr²h Cylinder surface area ✅2πrh+2πr² Slope of horizontal line ✅0 Slope of vertical line ✅undefined Distance formula ✅d = √[( x₂ - x₁)² + (y₂ - y₁)²] x² - y² ✅(x-y)(x+y) x² - 2xy + y² ✅(x-y)² x² + 2xy + y² ✅(x+y) ² Concept 1: Units Digits ✅23 *62 = units digit = 6 Concept 2: ✅Numbers raised to powers follows patterns Pattern 1: 0, 1, 5, 6 always the same Pattern 2: 4, 9 odd powers = (4,4), (9,9) , even powers have same = (4,6), (9,1) Pattern 3: 2, 3, 7, 8 repeat once every 4th power (2, 2), (2, 4), (2, 8), (2, 6) (3, 3), (3, 9), (3,7), (3, 1) (7,7), (7,9), (7,3), (7,1) (8,8), (8,4), (8,2), (8,6) In a DS problem, which grid do we use when starting with statement 1? ✅AD, BCE In a DS problem, which grid do we use when starting with statement 2? ✅BD, ACE y% of x = 100 (rewrite) ✅y/100 * x = 100 simplify (1/y - 1)/(1 + 1/y) ✅(1-y)/(y+1) is p odd? -- (1) cube root of p is odd (2) pcubed is odd ✅A Joanna bought only .15 stamps and .29 stamps. how many .15 stamps did she buy? -- 1. she bought 4.4 worth of stamps 2. she bought an equal number of .15 stamps and .29 stamps ✅A sqrt(4.8 * 10^9) is closest to what # ✅70k Distance between two points (X,Y) on a number line = ✅Abs(x -y)!! If a and b are pos int, is a/b < 9/11? (1). a/b < .818 (2). b/a > 1.223 ✅Reduce first fraction to 11 a < 9 b , do the same for (1) and (2). Answer = D Is RST = 1? (1) RS = 1 (2) ST = 1 ✅No. 5 x 1/5 x 5 = 5 (0.0025)(.025)(.00025) x 10^k . what is the least possible value if we want the number to be an integer? ✅12. 10^ -4 * 10 ^ -3 * 10^ -5. add up = 12 A merchant discounted 2 items of clothing. Which of the two was discounted at a greater $ amt? (1) the % discount on item 1 was 2 points greater than the % discount on item 2 (2) Before the discounts, item 1 was $10 less than item 2 ✅E. Neither one gives info abt the total price of the items which you need in order to find the price difference between the two. Factor these in the form (x+y)(x -y): (1 -n^4) and (a -b) ✅(1+n^2)(1+n)(1 -n) and (sqrt(a) + sqrt(b))(sqrt(a) - sqrt(b)) If (x-1)^2 = 400, what could be the value of x - 5 ✅16, -24 Working simultaneously at their respective constant rates, Machines A and B produce 800 nails in x hours. Working alone at its constant rate, Machine A produces 800 nails in y hours. In terms of x and y, how many hours does it take Machine B and A to produ ce 800 nails? ✅(a+b)x = 800 and (a)y = 800, (800/y + b) = 800/x, (800/y + 800/b) = 800/x, plug smart numbers (8 and 100) then test answer choices. remember to change b to 800/b because it is a rate Seven pieces of rope have an average (arithmetic mean) length of 68 CM and a median length of 84 CM. If the length of the longest piece of rope is 14 CM more than 4 times
