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Tandem Cycling Triplets Peter, Reeta and Nikita have two ways for getting home from school each day: cycle on a tandem bike or walk. The bike can carry either one or two riders at a time. Regardless of the number of people pedalling, cycling speed is 5 times walking speed. The triplets always leave school at the same time and always use the same path between school and home, whether walking or cycling. The school is 5 km from home and their walking speed is 4 kilometres per hour. a On Monday, Nikita and Peter cycle and Reeta walks. On reaching the point four-fifths of the way home the bike gets a puncture, so Nikita and Peter walk the rest of the way home. How far from school is Reeta when the cyclists arrive home? b On Tuesday, Peter and Reeta ride the bike and Nikita walks. When the cyclists arrive home, Peter hops off the bike and Reeta rides back towards school to collect Nikita. How far from school is Nikita when Reeta reaches her? c On Wednesday, Reeta and Nikita take the bike and Peter walks. When the cyclists are halfway home, Reeta off and walks the rest of the way, while Nikita heads back to pick up Peter. How far from school is Reeta when her siblings pass her on the bike? d On Thursday, it is Reeta's turn to walk. Peter drops Nikita off at a certain point leaving her to walk home. Meanwhile he returns to pick up Reeta and they cycle home together. If all three arrive home at the same time, how far from school are the drop-off and pick-up points?

Respuesta :

The distance between Reeta and the school when the cyclists arrive the home for this case is found to be 2 km

How to form mathematical expressions from the given description?

You can represent the unknown amounts by the use of variables. Follow whatever the description is and convert it one by one mathematically. For example, if it is asked to increase some items by 4, then you can add 4 in that item to increase it by 4. If something is, for example, doubled, then you can multiply that thing by 2 and so on methods can be used to convert descriptions to mathematical expressions.

How to find the speed of an object?

If the object is going linearly, and at a constant speed, then the speed of that object is given by the distance it travelled to the time it took to travel that distance.

If the object travelled D distance in T units of time, then that object's speed is

[tex]Speed = \dfrac{D}{T}[/tex]

Given that:

  • Distance from school to home = 5 km
  • Walking speed = 4 km / hours
  • Cycling speed = 5 times walking speed = 20 km / hour
  • They all go and come together to and from school/home.
  • On Monday: Nikita and Peter are coming by cycle, and Reeta walks.
  • Cycle punctures at four-fifth of the way home = [tex]\dfrac{4}{5}\times 5[/tex] from school (as they're coming towards home, so went from school)
  • After a puncture, cyclists walk to home
  • To find the Distance of Reeta from school when the cyclist reaches home.

Suppose at time 0 hours, all three people departed from school (on that Monday).

After 't' hours, suppose the cycle gets punctured.

Then, as the cycle was going by 20 km/hour speed, so in 't' hours, it must have covered d kilometres (suppose),

then we get:

[tex]S =\dfrac{D}{T}[/tex]

[tex]20=\dfrac{d}{t}[/tex]

d = 20t

This distance is measured from school. But we know that this distance is 4 km, so we get:

20t = 4

t  =  1 / 4

The remaining 1 km (as the home is 5 km away from school and 4 km is already travelled) is walked by Cyclists. And walking speed is 5 km/hour, so let they take T hours to travel that 1 km walking, then we get:

5 =  1 / T

t = 0.2 hours

So, the total time cyclists took to reach home from school is: 0.2+0.2=0.4 hours

Reeta is walking that whole 5 km.

The time the cyclist reached home, Reeta had walked for 0.4 hours as they had started at the same time, and it took cyclists 0.4 hours to reach home.

Thus, we have:

Time is taken 0.4 hours, speed of Reeta = walking speed= 5 km/hour, then we get:

D = S x T

D = 5 x 0.4 = 2 km

So Reeta was 2 km away from school when cyclists reached home on that Monday.

Thus, the distance between Reeta and the school when the cyclists arrive at the home for this case is found to be 2 km

Learn more about forming equations here:

brainly.com/question/11938672

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