Question

ПОМОГИТЕ ДАМ 10 БАЛЛОВ
Peter, Jamal and Khan were on their way to a resort. Peter drove of the journey at a constant speed of 64 km/h. Jamal took over and drove of the journey for 20 min at 5 12 a constant speed of 60 km/h. Khan then took over and drove the remaining journey. (a) How far did Jamal drive? (b) How many minutes did Peter drive?​

Answer 1

Ответ:

Пошаговое объяснение: (a) To find the distance Jamal drove, we need to know how far Peter drove and subtract it from the total distance of the journey.

Let's assume that the total distance of the journey is d km.

Peter drove the first part of the journey at a constant speed of 64 km/h. Let t be the time in hours that Peter drove, then:

d/3 = 64t

Simplifying this equation gives us:

t = d/192

Jamal then drove for 20 minutes at a constant speed of 60 km/h. Converting 20 minutes to hours gives us 1/3 hour.

So, the distance that Jamal drove is:

d/3 - 60(1/3) = d/3 - 20

(b) Peter drove the first part of the journey, which is d/3 km. We already know that he drove at a constant speed of 64 km/h. We can use the formula:

distance = speed x time

to find how long Peter drove for.

Let t be the time in hours that Peter drove. Then:

d/3 = 64t

Solving for t gives us:

t = d/192

We can convert this to minutes by multiplying by 60:

t = (d/192) x 60 = d/3 minutes

Therefore, Peter drove for d/3 minutes.