William traveled by scooter at an average speed of 62 miles per hour. Then, he traveled by car at an average speed of 36 miles per hour. In total he traveled 118 miles for 2 hours. How many minutes did William travel by car? ( Round to the nearest minute)
distance = rate * time (ds=distance on scooter) (dc=distance on car) -------------------- ds = rs * ts dc = rc * tc (rc is rate of car; rs is rate of scooter; ts is time on scooter; tc is time on car)
we already know rs and rc
yes
ds = 62 * ts dc = 36 * tc dt = total distance = 118 =62 * ts + 36 * tc tt = total time = 2 = ts + tc
these are all of the equations we need, do you know how to solve for ts and tc. We have 2 equations and 2 unknowns at this point
Wait, let me try.
oh, also remember to convert hours to minutes once you have solved for tc
ok
can you show me the steps. Im kind of stuck
118 = 62 * ts + 36 * tc 2 = ts + tc we will use substitution
ts = 2-tc
ok
substitute (2-tc) wherever there is a ts in the following equation 118 = 62 * ts + 36 * tc becomes 118 = 62 * (2-tc) + 36 * tc
can you solve this equation?
not really
start by distributing the 62 into the (2 - tc)
124-62*ts
i mean 124 - 62*tc
124-26tc
now put the rest of the equation around what you got
-6 - 26tc
118 = 124 - 26*tc + 36*tc Next step is to combine like terms
oops my equation is wrong
Yea i Was about to say that
118 = 124 - 62*tc + 36*tc
i think you just left out an equal sign
Yea
-6= -26tc
Solve for tc. just remember to convert your answer to tc, which is in hours, into units of minutes (which is what the problem asks for).
ok
i got 0.230769 repeating...
Can you help me out?
that fine, this number is in hours. we are interested in calculating the number of minutes spent in the car. Therefore, we need to convert hours to minutes.
ok
so we do 60/5
and get 14 minutes?
\[\frac{number of hours}{1}*\frac{60 minutes}{1hour}=numberofminutes\]
your answer seems right
Yes! Thank You!
great!
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