Gmat Prep Quant Practise
PARVEEN CHAUDHARY SERIAL GMAT TAKER MOBILE : 9990160414 E-MAIL : gmat_professor@yahoo.com
SETS
1. For an overlapping sets problem it is best to use a double set matrix to organize the information and solve. Fill in the information in the order in which it is given. Of the films Empty Set Studios released last year, 60% were comedies and the rest were horror films. Horror Comedies Total Films Profitable Unprofitable Total 0.6x 0.4x x 75% of the comedies were profitable, but 75% of the horror moves were unprofitable. Comedies Profitable Unprofitable Total 0.75(0.6x) 0.6x 0.75(0.4x) 0.4x x Horror Films Total
If the studio made a total of 40 films... Comedies Profitable Unprofitable Total 0.6(40) = 24 0.75(24) = 18 0.75(16) = 12 0.4(40) = 16 Horror Films Total
x= 40
Since each row and each column must sum up to the Total value, we can fill in the remaining boxes. Comedies Horror Films Total
Profitable Unprofitable Total
18 6 24
4 12 16
22 18 40
The problem seeks the total number of profitable films, which is 22. The correct answer is E.
2. For an overlapping sets problem we can use a double-set matrix to organize our information and solve. Because the values are in percents, we can assign a value of 100 for the total number of interns at the hospital. Then, carefully fill in the matrix based on the information provided in the problem. The matrix below details this information. Notice that the variable x is used to detail the number of interns who receive 6 or more hours of sleep, 70% of whom reported no feelings of tiredness. Tired Not Tired TOTAL 6 or more hours Fewer than 6 hours .3x 75 .7x x 80
TOTAL 100 In a double-set matrix, the sum of the first two rows equals the third and the sum of the first two columns equals the third. Thus, the boldfaced entries below were derived using the above matrix. Tired 6 or more hours Fewer than 6 hours TOTAL 6 75 81 Not Tired 14 5 19 TOTAL 20 80 100
We were asked to find the percentage of
SETS
1. For an overlapping sets problem it is best to use a double set matrix to organize the information and solve. Fill in the information in the order in which it is given. Of the films Empty Set Studios released last year, 60% were comedies and the rest were horror films. Horror Comedies Total Films Profitable Unprofitable Total 0.6x 0.4x x 75% of the comedies were profitable, but 75% of the horror moves were unprofitable. Comedies Profitable Unprofitable Total 0.75(0.6x) 0.6x 0.75(0.4x) 0.4x x Horror Films Total
If the studio made a total of 40 films... Comedies Profitable Unprofitable Total 0.6(40) = 24 0.75(24) = 18 0.75(16) = 12 0.4(40) = 16 Horror Films Total
x= 40
Since each row and each column must sum up to the Total value, we can fill in the remaining boxes. Comedies Horror Films Total
Profitable Unprofitable Total
18 6 24
4 12 16
22 18 40
The problem seeks the total number of profitable films, which is 22. The correct answer is E.
2. For an overlapping sets problem we can use a double-set matrix to organize our information and solve. Because the values are in percents, we can assign a value of 100 for the total number of interns at the hospital. Then, carefully fill in the matrix based on the information provided in the problem. The matrix below details this information. Notice that the variable x is used to detail the number of interns who receive 6 or more hours of sleep, 70% of whom reported no feelings of tiredness. Tired Not Tired TOTAL 6 or more hours Fewer than 6 hours .3x 75 .7x x 80
TOTAL 100 In a double-set matrix, the sum of the first two rows equals the third and the sum of the first two columns equals the third. Thus, the boldfaced entries below were derived using the above matrix. Tired 6 or more hours Fewer than 6 hours TOTAL 6 75 81 Not Tired 14 5 19 TOTAL 20 80 100
We were asked to find the percentage of