PP-T2-PS76

[Huang Hsin-Yi]

76. 8721-!-item-!-187;#058&006602
A hiker walking at a constant rate of 4 miles per hour is passed by a cyclist traveling in the same direction along the same path at a constant rate of 20 miles per hour. The cyclist stops to wait for the hiker 5 minutes after passing her, while the hiker continues to walk at her constant rate. How many minutes must the cyclist wait until the hiker catches up?

h走4mile/hour, c走20mile/hour, c在超過h以後,等h五分鐘
當h開始走時, c要等幾分鐘等h追上

好奇怪呀,h不是在c前面嗎,為何 c要等h勒

(A)
(B) 15
(C) 20
(D) 25
(E)
Ans:C

要如何算?

[小花]

請教一下
我的PP T2 PS 沒有76題
您怎麼會有呢?
要去哪裡下載?

[Huang Hsin-Yi]

在對岸cd數學篇當中
回頭找,找不到放在那
你e-mail給我,我e給你
不過題目不是挺完整,刪一刪大概還有一半可以練習

[Huang Hsin-Yi]

help! help! help!

[sunnyblue13s]

H: 4m/h=4m/60=1/15m

C:20m/h...........=5/15m

則{(5/15-1/15)*5}/(1/15)=20

[Huang Hsin-Yi]

H: 4m/h=4m/60=1/15m

C:20m/h...........=5/15m

則{(5/15-1/15)*5}/(1/15)=20
你這個式很像,兩個人一起走了五分鍾後, c停下來要等幾分鐘,h才能趕上

這和我理解的不同,請問
The cyclist stops to wait for the hiker 5 minutes after passing her, while the hiker continues to walk at her constant rate

如何解釋呀?

[chiungfen]

我覺得sunnyblue13s 寫的沒錯~~~我來解釋一下好了

H: 4m/h=4m/60=1/15m .....一分鐘1/15miles

C:20m/h...........=5/15m......一分鐘5/15miles

SO C比h快了一分鐘4/15miles. then 題目說C超過H時會等H 5分鐘，但沒說超過多少miles......

而我們已知的是一分鐘4/15miles, so 5分鐘是20/15miles.(等5分鐘的話，c會比h多了20/15miles)

注意，題目又說hiker continues to walk at her constant rate, so H以同樣的速率前進(1/15miles)

若以一分鐘1/15miles 前進，那20/15miles 要幾分鐘呢??? so C要等上h20分鐘囉~~~

哈~~~寫的很長…慢慢想一想嚕

[Huang Hsin-Yi]

謝謝chiungfen
我想我懂了