the time taken, t, for a journey of fixed distance is inversely proportional to the average speed of travel, s. If the journey takes 2 hours 15 minutes travelling at an average speed of 50km/hour, how long will it take if the average speed is 27km/hour. Give your answer in hours and minutes​

Respuesta :

[tex]\huge{\color{red}{\fbox{\textsf{\textbf{Answer}}}}} [/tex]

4 hours 12 minutes

Step-by-step explanation:

We need to convert time in hours by diving 15 by 60

[tex] \sf 2 \frac{15}{60} \\ \\ \sf 2 \frac{1}{4} [/tex]

as it is mixed fraction we will convert into improper

[tex] \sf \frac{(2 \times 4) + 1}{4} \\ \\ \sf time = \frac{9}{4} hours[/tex]

Now we need to find distance

[tex] \sf \green {distance = speed \times time}[/tex]

Here speed is 50km/h

[tex] \sf \implies distance = 50 \times \frac{9}{4}km \\ \\ \sf \implies distance = \frac{25 \times 9}{2}km \\ \\ \sf \implies distance = \frac{225}{2} km \\ \\ \sf \implies \red {distance = 112.5km}[/tex]

Now we have to have time at new speed at 27km/h

and distance is same

[tex] \sf \pink{ time = \frac{distance}{speed} }[/tex]

Now substituting the value of speed and distance

[tex] \sf \implies time = \frac{112.5}{27} [/tex]

Now we will remove point(.) from the distance by multiplying 10 with 27

[tex] \sf \implies time = \frac{1125}{27 \times 10} \\ \\ \sf \implies time = \frac{41.6}{10} [/tex]

now we will convert it into mixed fraction

[tex] \sf \implies time = 4 \frac{1}{5} hours [/tex]

Now we will convert fraction hours into minutes by multiply with 60

[tex] \sf \implies time = 4 \: hours \: \frac{1}{5} \times 60 \: minutes \\ \\ \sf \implies \orange{ time = 4 \: hours \: 12 \: minutes}[/tex]