WRT Practice PS Set – 1
Work & Rate: Level 1
1.
If a machine can produce 120 widgets in 4 hours, what is its rate of production per hour?
Solution (C):
\( Rate = \frac{Work}{Time} = \frac{120}{4} = 30 \) widgets/hour.
2.
John can paint a room in 5 hours. What fraction of the room can he paint in 2 hours?
Solution (B):
Rate = \( \frac{1}{5} \) room per hour.
Work = Rate \(\times\) Time = \( \frac{1}{5} \times 2 = \frac{2}{5} \).
3.
It takes 3 printers to print 300 pages in 10 minutes. How many pages can 1 printer print in 10 minutes?
Solution (D):
If 3 printers print 300 pages, 1 printer prints \( 300 \div 3 = 100 \) pages in the same time.
4.
If 5 kg of apples cost $20, how much do 8 kg of apples cost?
Solution (A):
Cost per kg = \( 20 \div 5 = \$4 \).
Cost for 8 kg = \( 8 \times 4 = \$32 \).
5.
A car travels at a constant speed of 60 miles per hour. How many miles does it travel in 1 hour and 30 minutes?
Solution (E):
Time = 1.5 hours.
Distance = Rate \(\times\) Time = \( 60 \times 1.5 = 90 \) miles.
6.
If 3 workers can build a wall in 6 days, how many days would it take 1 worker to build the same wall?
Solution (B):
This is an inverse proportion. Fewer workers take more time.
Total work = \( 3 \text{ workers} \times 6 \text{ days} = 18 \) worker-days.
1 worker will take \( \frac{18}{1} = 18 \) days.
7.
A typist types 50 words per minute. How many minutes will it take to type a 2000-word essay?
Solution (C):
Time = \( \frac{\text{Work}}{\text{Rate}} = \frac{2000}{50} = 40 \) minutes.
8.
If water flows into a tank at a rate of 10 gallons per minute, how much water enters the tank in 45 seconds?
Solution (D):
45 seconds = \( \frac{45}{60} = \frac{3}{4} \) minutes.
Volume = \( 10 \times \frac{3}{4} = 7.5 \) gallons.
9.
A map scale is 1 inch = 10 miles. How many inches represent 25 miles?
Solution (B):
\( \frac{1 \text{ in}}{10 \text{ mi}} = \frac{x}{25 \text{ mi}} \).
\( x = \frac{25}{10} = 2.5 \) inches.
10.
If it takes 2 hours to mow 3 lawns, how many lawns can be mowed in 10 hours?
Solution (A):
Rate = \( \frac{3 \text{ lawns}}{2 \text{ hours}} = 1.5 \) lawns/hour.
In 10 hours: \( 1.5 \times 10 = 15 \) lawns.
Score: 0 / 0