Question

What is the average speed of a biker if she biked 4 1/4 of a mile in 25 minutes?

Answer 1

Explanation:

What is the average speed of a biker if she biked 4 1/4 of a mile in 25 minutes?

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rate = distance/time

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rate = (17/4)/(25/60) = (17/4)(60/25) = (17*3/5) = 51/5 = 10.2 mph

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Answer 2

`\frac{10.2\text{ miles}}{\text{ hour}}`

Explanation:

We are asked to find the speed of a biker, who biked 4 1/4 of a mile in 25 minutes.

To find average speed of the biker, we will divide total distance by total time taken.

`4(1)/(4)\text{ miles}/ 25\text{ min}`

Convert mixed fraction into improper fraction:

`4(1)/(4)\Rightarrow (4*4+1)/(4)=(16+1)/(4)=(17)/(4)`

`(17)/(4)\text{ miles}/ (25)/(1)\text{ min}`

Convert to multiplication problem by flipping the 2nd fraction:

`(17)/(4)\text{ miles}* \frac{1}{25\text{ min}}`

`\frac{17\text{ miles}}{100\text{ min}}`

Convert minutes to hour:

`\frac{17\text{ miles}}{100\text{ min}}* \frac{\text{60 min}}{\text{1 hour}}`

`\frac{17\text{ miles}}{10}* \frac{6}{\text{1 hour}}`

`\frac{102\text{ miles}}{\text{10 hour}}`

`\frac{51\text{ miles}}{\text{5 hour}}`

`\frac{10.2\text{ miles}}{\text{ hour}}`

Therefore, the average speed of biker is 10.2 miles per hour.