ANSWER KEY AND EXPLANATIONS

1. The correct answer is (C). 6,594 papers ÷ 314 clerks = 21 papers filed by each clerk in 10 minutes; 21 papers ÷ 10 minutes = 2.1 papers per minute filed by the average clerk.
2. The correct answer is (A). It takes one man 42 × 4 = 168 days to complete the job, working alone. If men are working (one man works half-days, the other three work full days), the job takes days.
3. The correct answer is (B). In seven hours, the clerk files 7 × 80 = 560 cards. Because 800 cards must be filed, there are 800 – 560 = 240 remaining.
4. The correct answer is (A). It takes one machine 3 × 4 = 12 days to complete the job. Two machines can do the job in 12 ÷ 2 = 6 days.
5. The correct answer is (B). At the end of the first half-hour, there are 500 – 25 = 475 forms remaining. If the first stenographer completed 25 forms in half an hour, her rate is 25 × 2 = 50 forms per hour. The combined rate of the two stenographers is 50 + 45 = 95 forms per hour. The remaining forms can be completed in 475 ÷ 95 = 5 hours. Adding the first half-hour, the entire job requires hours.
6. The correct answer is (D). 36 lines × 11 words = 396 words on each page; 125 pages × 396 words = 49,500 words copied in five days; 49,500 ÷ 5 = 9,900 words copied in one day. 12 words × 30 lines = 360 words on each page; pages copied in one day; pages copied in six days.
7. The correct answer is (A). If A can finish the job alone in 5 hours, A can do of the job in one hour. Working together, A and B can complete the job in 2 hours; therefore, in one hour, they finish half the job. In one hour,B alone completes of the job. It would take hours, or hours, to finish the whole job alone.
8. The correct answer is (A). She must type 7 × 25 = 175 lines. At the rate of one line per 10 seconds, the job takes 175 × 10 = 1,750 seconds. 1,750 seconds ÷ minutes, or 29 minutes and 10 seconds.
9. The correct answer is (B). All five clerks working together process a total of 1,100 + 1,450 + 1,200 + 1,300 + 1,250 = 6,300 letters per hour. After two hours, they process 6,300 × 2 = 12,600 letters. Of the original 24,000 letters, there are 24,000 – 12,600 = 11,400 letters remaining. Clerks A, B, and E working together process a total of 1,100 + 1,450 + 1,250 = 3,800 letters per hour. It takes them 11,400 ÷ 3,800 = 3 hours to process the remaining letters.
10. The correct answer is (C). The job could be completed by one worker in 18 × 26 = 468 days. Completing the job in 12 days requires 468 ÷ 12 = 39 workers.