Laura B. answered • 10/19/21
Stress Free Studies! Math Tutor with MEd. UCSD, BS Physics UCSC
Strategy: Use D=RT and the relationship between the two bus rates to substitute and solve.
D is the total distance between the busses. R stands for the bus speed (rate of travel). t is time.
Sinces the busses are headed in opposite directions, add the distance each bus travels together to get the total distance between the two.
D = (R1)t + (R2)t and R1=R2+15
Substitute in for R1
D = (R2+15)t + (R2)t
Now put in all the known values you have, and solve for R2.
Once you have R2, remember to add 15km/h to get R1.
You've got an answer! Now let's check it!
Take values you found and plug them in to the original equation:
D = (R1)t + (R2)t
If the D you get out is 1050km, your work is correct!
I hope this helps! See my video for a more detailed working of the problem, and let me know if you'd ever like to do some tutoring.
Cheers,
Laura
Laura B.
Thanks! I figure it's always best to not just be right but to *know* you're right, eh? Please do look me up to book a session if you're ever stuck again!10/21/21
Stephanie C.
Laura - You're an absolute angel! I'm very thankful for you taking the time to break down my question and help me better understand how to figure out the answer, but also the alternative strategy of rechecking the answers to assure the numbers are correct. Thank you, Stephanie Chavez10/21/21