A plane traveled k miles in its first 96 minutes of flight time. If it

Question

A plane traveled k miles in its first 96 minutes of flight time. If it completed the remaining 300 miles of the trip in t minutes, what was its average speed, in miles per hour, for the entire trip?

(A)  \frac{60(k + 300)}{(96 + t)}

(B)  \frac{(kt + 96(300))}{96t}

(C)  \frac{(k + 300)}{60(96 + t)}

(D)  \frac{5k}{8} + \frac{60(300)}{t}

(E)  \frac{5k}{8} + 5t

rohit8865 · Accepted Answer

total distance covered = K+300 miles
total time taken = 96+t minutes or (96+t)/60 hrs

avg speed = total distance / total time
= (k+300) / {(96+t)/60 } miles/hr
=60 ( k + 300 )/96 + t

Ans A

Bunuel · Answer

Check other  Conversion problems  to practice from our  Special Questions Directory .

JeffTargetTestPrep · Answer

We are given that a plane traveled k miles in 96 minutes. Since we need the average speed in miles per hour we can convert 96 minutes to hours.

96 minutes = 96/60 = 8/5 hours

We are also given that the plane completed the remaining 300 miles in t minutes. We must also convert t minutes to hours.

t minutes = t/60 hours

Now we can calculate the average speed for the entire trip, using the formula for average speed.

Average speed = total distance/total time

Average speed = (k + 300)/(8/5 + t/60) = (k + 300)/(96/60+t/60)

Average speed = (k + 300)/((96 + t)/60)

Average speed = 60(k + 300)/(96 + t)

Answer: A

fskilnik · Answer

Simple application of UNITS CONTROL, one of the most powerful tools of our method!

? = \frac{{\left }}{{\left }}\,\,\frac{{{	ext{miles}}}}{{\min }}\,\,\,\left( {\frac{{60\,\,\min }}{{1\,\,\,{	ext{h}}}}\,\,\begin{array}{*{20}{c}}
 
earrow \ 
 
earrow 
\end{array}} ight)\,\,\, = \,\,60 \cdot \left( {\frac{{\left }}{{\left }}} ight)\,\,\,{	ext{mph}}\,\,\,

(Arrows indicate licit converter.)

\left  = k + 300

\left \,\,{	ext{ = }}\,\,96 + t

? = \frac{{60\,\left( {k + 300} ight)}}{{96 + t}}\,\,

This solution follows the notations and rationale taught in the GMATH method.

Regards,
Fabio.

EMPOWERgmatRichC · Answer

Hi All,

We're told that a plane traveled K miles in its first 96 minutes of flight time and it completed the remaining 300 miles of the trip in T minutes. We're asked for the average speed of the plane, in miles per hour, for the entire trip. This question can be solved by TESTing VALUES.

IF... K = 300 and T = 96... 
then the plane traveled 300+300 = 600 miles in 96+96 = 192 minutes

We're asked for the average speed in miles/HOUR though, so we have to go the extra step of converting minutes to hours. This can be done in a couple of different ways: either by dividing 192 by 60 OR by multiplying the fraction (600/192) by 60. If you take the second approach, then you can actually avoid the physical math and just look for the answer that matches the 'look' of the fraction: 60(600/192). There's only one answer that matches...

Final Answer:  A

GMAT assassins aren't born, they're made, 
Rich

sashiim20 · Answer

Total Distance  = k + 300

Total Time (in minutes)  = 96 + t

Total Time (in hours)  = \frac{96}{60} + \frac{t}{60} = \frac{96 + t}{60}

Average Speed  = \frac{Distance}{Time}

Average Speed  = \frac{(k +300)}{\frac{(96+t)}{60}}   = \frac{60 (k+300)}{(96+t)}

Answer A

KanishkM · Answer

KeyWord =miles per hour

60 mins 1 hr 
1 min = 1/60 hr
96 mins = 96/60 hr = 8/5 hr

8/5 hr, k miles

1 min = 1/60 hr
t mins = t/60 hr

Average speed = 300 + k /

\frac{60(k + 300)}{(96 + t)}

A

nahid78 · Answer

total distance= K+300 miles
total time= 96+t minutes or (96+t)/60 hrs
A

Ruchi007 · Answer

Bunuel  Why can't we apply the formula 2uv/(u+v) over here? u,v are the speeds in the 2 intervals.

Bunuel · Answer

You can get the average speed with that formula when the two intervals are equal, which is not the case in this question.

If you assume k = 300 miles, with that formula you'd get:

\frac{2*\frac{300 }{(\frac{96}{60})}*\frac{300}{(\frac{t}{60})} }{\frac{300 }{(\frac{96}{60})}+ \frac{300}{(\frac{t}{60})} }=\frac{36000}{t + 96} .

And if you substitute k = 300 ins option A you'd get the same:  \frac{60(300 + 300)}{96 + t}=\frac{36000}{t + 96}

Hope it's clear.

DanTheGMATMan · Answer

Stick to the plan. Total Distance over total time and then convert:

https://www.youtube.com/watch?v=f5fq5iDMy0E

bumpbot · Answer

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A plane traveled k miles in its first 96 minutes of flight time. If it

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