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Unformatted text preview: r the 11 1 student: 7 × 7 = 49 . The probability of picking the same student twice, added to the probability of not picking the same student twice, equals 1. 1 So to answer the question, subtract 49 from 1. (C) Let x = the number of quarters in the bank (this is the numerator of the probability formula’s fraction), and let x + 72 = the total number of coins (the fraction’s denominator). Solve for x:
1 x = 4 x + 72 x + 72 = 4 x 72 = 3x 24 = x ( )( ) 2. (C) The two flight paths form the legs of a right triangle, the hypotenuse of which is the shortest distance between the trains (40 miles). As the next figure shows, a 120° turn to either the left or right allows for two scenarios (point T is the terminal): 4. 5. The correct answer is 1/6. Given that the ratio of the large circle’s area to the small circle’s area is 3:1, the area of the “ring” must be twice that of the small circle. Hence the probability of randomly selecting a point in the outer ring is 2 1 . The shaded area accounts for 4 of the ring, 3 and so the probability of selecting a point in the 2121 shaded area is × = = .
3 4 12 6 As the figures show, the two flight paths, along with a line segment connecting the two planes, form a 30°-60°-90° triangle with sides in the ratio 1: 3 :2. To answer the question, solve for the length of the longer leg (x), which is opposite the 60° angle. One way to solve for x is by applying either the sine or cosine function. Applying the function sin60° = set the value of this function equal to
x opposite 40 hypotenuse , then solve for x:
3 , 2 www.petersons.com 310 Chapter 16 3x = ; 2 x = 40 3 ; x = 20 3 . The question 2 40 7. (D) The figure shows the graph of y = 2x, asks for an approximate distance in miles. Using 1.7 as the approximate value of (20)(1.7) = 34. 3. (D) The entire area between the two circles is the area of the larger minus the area of the smaller. Letting that area equal A:
A = π ( 2r ) − π r 2
2 whose slope (2) is twice the negative reciprocal
1 of − 2 , which...
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This note was uploaded on 08/15/2010 for the course MATH a4d4 taught by Professor Colon during the Spring '10 term at Embry-Riddle FL/AZ.
- Spring '10