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๐Ÿ“ Distance formula d=rt (11 MCQs)

๐Ÿ“– From Digital SAT Algebra โ€ข 2. Linear Equations And Inequalities โ€ข 11 questions available

What is Distance formula d=rt?

Definition:
The distance formula d=rtd = rt relates distance dd, rate (speed) rr, and time tt. It states that distance equals the product of rate and time. This formula is used to solve motion problems where one of the three variables is unknown.

Working:
To find rate, solve r=d/tr = d/t; to find time, solve t=d/rt = d/r. For example, if a car travels 150 miles in 3 hours, d=150d = 150, t=3t = 3, so r=150/3=50r = 150/3 = 50 mph.

Example:
A train travels 240 miles at a speed of 60 mph. Find the time. Using d=rtd = rt, 240=60t240 = 60t, divide by 60: t=4t = 4 hours.

Reason:
This formula is a fundamental real-world application of linear equations, allowing calculation of distance, speed, or time when two are known.

3
Easy
5
Medium
3
Hard

๐Ÿ“ All Distance formula d=rt MCQs

Q1. A cyclist travels at 1818 km/h for 2.52.5 hours. Which expression correctly models the distance traveled before calculating the answer?

A.18+2.518+2.5
B.18(2.5)18(2.5) โœ…
C.18รท2.518\div2.5
D.2.5รท182.5\div18
๐Ÿ’ก Difficulty: easy | โœ… Correct: B

๐Ÿ“– Explanation: The distance is found by multiplying rate by time, so d=rt=18(2.5)d=rt=18(2.5). The other operations confuse the roles of rate and time and therefore do not represent the physical situation correctly.

Q2. Two buses leave the same terminal at the same time. Bus A travels at 6060 km/h and Bus B at 7272 km/h. After 33 hours, how much farther has Bus B traveled?

A.1212 km
B.3636 km โœ…
C.180180 km
D.216216 km
๐Ÿ’ก Difficulty: medium | โœ… Correct: B

๐Ÿ“– Explanation: Bus A travels 60(3)=18060(3)=180 km, while Bus B travels 72(3)=21672(3)=216 km. Their difference is 216โˆ’180=36216-180=36 km. Comparing both distances prevents the common error of using only one rate.

Q3. A delivery driver must travel 240240 km. If the average speed is 8080 km/h, which reasoning correctly determines the travel time?

A.Multiply 240240 by 8080, giving 19,20019{,}200 hours
B.Subtract 8080 from 240240, giving 160160 hours
C.Divide 240240 by 8080, giving 33 hours โœ…
D.Divide 8080 by 240240, giving 1/31/3 hour
๐Ÿ’ก Difficulty: medium | โœ… Correct: C

๐Ÿ“– Explanation: Starting with d=rtd=rt, solving for time gives t=d/rt=d/r. Therefore t=240/80=3t=240/80=3 hours. Multiplying distance and rate produces incorrect units, while reversing the division gives hours per kilometer instead of hours.

Q4. A student says that traveling 4545 km/h for 44 hours gives 4949 km because 45+4=4945+4=49. What is the best analysis of the student's error?

A.The student should subtract time from rate
B.The student should multiply rate by time because each hour contributes 4545 km โœ…
C.The student should divide time by rate because hours are smaller
D.The student should multiply distance by time instead
๐Ÿ’ก Difficulty: easy | โœ… Correct: B

๐Ÿ“– Explanation: The student's mistake is treating rate and time as quantities that can simply be added. A rate of 4545 km/h means 4545 kilometers are covered each hour, so four hours produce 45(4)=18045(4)=180 km.

Q5. A car travels 150150 km in the first 22 hours and then 9090 km in the next 1.51.5 hours. What is its average rate for the entire trip?

A.6060 km/h
B.68.668.6 km/h โœ…
C.7272 km/h
D.8080 km/h
๐Ÿ’ก Difficulty: hard | โœ… Correct: B

๐Ÿ“– Explanation: The total distance is 150+90=240150+90=240 km and the total time is 2+1.5=3.52+1.5=3.5 hours. Thus the average rate is 240/3.5โ‰ˆ68.6240/3.5\approx68.6 km/h. Averaging the two rates directly would ignore unequal time intervals.

Q6. A distance-versus-time graph shows a straight line passing through (0,0)(0,0) and (5,300)(5,300), where time is measured in hours and distance in kilometers. What does the slope represent?

A.The total travel time
B.The starting distance
C.The travel rate of 6060 km/h โœ…
D.The final distance of 300300 km
๐Ÿ’ก Difficulty: medium | โœ… Correct: C

๐Ÿ“– Explanation: For a distance-versus-time graph, slope equals change in distance divided by change in time. Here the slope is 300/5=60300/5=60 km/h, so it represents the constant travel rate rather than total distance or elapsed time.

Q7. A runner increases speed from 88 m/s to 1010 m/s while keeping the running time fixed at 3030 seconds. By how much does the distance increase?

A.2020 m
B.3030 m
C.6060 m โœ…
D.300300 m
๐Ÿ’ก Difficulty: medium | โœ… Correct: C

๐Ÿ“– Explanation: At 88 m/s for 3030 seconds, the runner covers 240240 m. At 1010 m/s for the same time, the distance is 300300 m. The increase is 300โˆ’240=60300-240=60 m, showing how distance changes proportionally with rate when time is fixed.

Q8. A student calculates the time for a 360360-km trip at 9090 km/h as 32,40032{,}400 hours by multiplying 360(90)360(90). Which correction best explains why this is wrong?

A.Distance and rate should be added
B.Time is found by dividing distance by rate, so 360/90=4360/90=4 hours โœ…
C.Time is found by multiplying distance by rate after converting kilometers to hours
D.The rate must be divided by distance, giving 1/41/4 hour
๐Ÿ’ก Difficulty: medium | โœ… Correct: B

๐Ÿ“– Explanation: Since d=rtd=rt, isolating time requires division: t=d/rt=d/r. Therefore t=360/90=4t=360/90=4 hours. The product 360(90)360(90) has units of kilometers squared per hour, which cannot represent a time measurement.

Q9. Two distance-time graphs are straight lines from the origin. Graph A reaches 180180 km at 33 hours, while Graph B reaches 160160 km at 22 hours. Which conclusion is correct?

A.Graph A represents the faster traveler
B.Graph B represents the faster traveler โœ…
C.Both travelers have the same rate
D.There is not enough information to compare their rates
๐Ÿ’ก Difficulty: hard | โœ… Correct: B

๐Ÿ“– Explanation: The slope gives the rate. Graph A has rate 180/3=60180/3=60 km/h, while Graph B has rate 160/2=80160/2=80 km/h. Therefore Graph B is steeper and represents the faster traveler despite having a smaller displayed distance.

Q10. A train travels 120120 km at 6060 km/h, stops for 3030 minutes, and then travels another 180180 km at 9090 km/h. What is the train's total elapsed time, including the stop?

A.3.53.5 hours
B.44 hours
C.4.54.5 hours โœ…
D.55 hours
๐Ÿ’ก Difficulty: hard | โœ… Correct: C

๐Ÿ“– Explanation: The first segment takes 120/60=2120/60=2 hours and the second takes 180/90=2180/90=2 hours. Adding the 0.50.5-hour stop gives 2+0.5+2=4.52+0.5+2=4.5 hours. Thus the correct choice is 4.54.5 hours, not 44 hours, because elapsed time includes the stop.

Q11. A vehicle must cover 420420 km in 66 hours. It spends 11 hour stopped, so it can travel for only 55 hours. What constant travel rate is required while the vehicle is moving?

A.7070 km/h
B.7575 km/h
C.8484 km/h โœ…
D.9090 km/h
๐Ÿ’ก Difficulty: easy | โœ… Correct: C

๐Ÿ“– Explanation: The available moving time is 6โˆ’1=56-1=5 hours. Using d=rtd=rt, the required rate is r=d/t=420/5=84r=d/t=420/5=84 km/h. Using all six hours would incorrectly ignore the stop and underestimate the necessary moving speed.

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