Applied Maths - Numerical Problems (boats, pipes, races)

Grade 12 Maths — Applied Maths - Numerical Problems (boats, pipes, races): 25 practice questions with instant scoring and explanations.

1. Upstream speed = Boat speed − Water current speed. If boat speed is 20 km/h and current is 5 km/h, upstream speed is:
2. Downstream speed = Boat speed + Water current speed. For the same boat and current, downstream speed is:
3. Time to travel d km upstream at speed u km/h is:
4. A boat travels 60 km downstream in 3 hours and 60 km upstream in 5 hours. Current speed is:
5. Pipes A and B can fill a tank in 6 hours and 9 hours respectively. Together they fill it in:
6. Pipe A fills at rate 1/6 per hour. Pipe B drains at rate 1/9 per hour. Net filling rate is:
7. A pipe can fill a tank in 6 hours. How much is filled in 2 hours?
8. If pipe A fills 1/4 per hour and pipe B fills 1/6 per hour, combined rate is:
9. Time to fill with combined rate of 5/12 per hour is:
10. In a race, A finishes 100m in 10 seconds. B finishes in 12 seconds. When A finishes, B is:
11. A's speed = 100/10 = 10 m/s, B's speed = :
12. If A runs 20m while B runs 18m, and they race 100m, when A finishes B has run:
13. Work done per day: if A completes a job in 10 days, A's work per day is:
14. A and B complete work in 6 and 8 days respectively. Together they complete in:
15. If A completes 2/5 of work in 4 days, A completes the full work in:
16. A and B work together for 2 days, then A leaves. B completes remaining in 4 days. A alone finishes in:
17. Current speed = (Downstream speed − Upstream speed)/2. If downstream is 14 km/h and upstream is 6 km/h, current is:
18. Boat speed = (Downstream + Upstream)/2. For above, boat speed is:
19. A pipe can fill 1/3 of tank in 1 hour. To fill completely it takes:
20. Two pipes fill at rates 1/a and 1/b per hour. Time to fill together is:
21. In a race of 400m, A gains 40m on B. When A finishes 400m, B has covered:
22. If A can do work in 6 days and B in 8 days, in 1 day together they do:
23. Speed of boat in still water 10 km/h, stream 2 km/h. Downstream speed:
24. Pipe A fills a tank in 6 h, B in 3 h. Together:
25. In a 100 m race, A beats B by 20 m. A's speed : B's speed =