Brainlytaoidn
Answered

Makakuha ng mga sagot ng eksperto sa iyong mga tanong sa IDNStudy.com. Alamin ang mga detalyadong sagot sa iyong mga tanong mula sa aming malawak na kaalaman sa mga eksperto.

Joe enters a race where he has to cycle and run.

He cycles a distance of 25 km, and then runs for 20 km. His average running speed is half of his average cycling speed.

Joe completes the race in less than 2½ hours, what can we say about his average speeds?

Assign Letters:

Formulas:

The race is divided into two parts:

Solve:

Sagot :

PROBLEM:

Joe enters a race where he has to cycle and run.He cycles a distance of 25 km, and then runs for 20 km. His average running speed is half of his average cycling speed.Joe completes the race in less than 2½ hours, what can we say about his average speeds?

ANSWER:

Assign Letters↓

1. Average running speed: s

2. So average cycling speed: 2s

Formulas↓

Speed = [tex] \large\frac{Distance}{Time} [/tex]

Which can be rearranged to:

Time = [tex]\large \frac{Distance}{Speed} [/tex]

The race is divided into two parts↓

→ CYCLING

Distance = 25 km

Average speed = 2s km/h

So Time = [tex]\frac{Distance}{Average\:Speed}[/tex]= [tex]\frac{25}{2s}hours[/tex]

→RUNNING

Distance = 20 km

Average speed = s km/h

So Time = [tex]\frac{Distance}{Average\:Speed}[/tex] = [tex]\frac{20}{s} hours[/tex]

So Joe completes the race in less than 2½ hours

Then the total time is < 2½

Solution to get the total time is below ↓

252s + 20s < 2½

Solve:

First → 252s + 20s < 2½

Then Multiply all terms by 2s↓

→ 25 + 40 < 5s

Then Simplify → 65 < 5s

Divide both sides by 5 → 13 < s

Swap sides so it's equal to → s > 13

So we already know that Joe average speed running is greater than 13 km/h and his average speed cycling is greater than 26 km/h.

#CarryOnLearning

Ang iyong aktibong pakikilahok ay mahalaga sa amin. Magpatuloy sa pagtatanong at pagbibigay ng mga sagot. Sama-sama tayong lumikha ng isang komunidad ng karunungan. Para sa mabilis at maasahang mga sagot, bisitahin ang IDNStudy.com. Nandito kami upang tumulong sa iyo.