SOLUTION: I need help to do a quantative analysis a situation diagram and to solve the problem on this one. My sister can walk from school to home in 40 minutes. I can walk from school to h

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Question 666179: I need help to do a quantative analysis a situation diagram and to solve the problem on this one.
My sister can walk from school to home in 40 minutes. I can walk from school to home in 30 minutes. Today I stayed for some extra help, and my sister was already 2/5 of the way home when I started. If I walk at my usual peed, can I catch my sister before she gets home? If "yes" exactly what fraction of the trip have we covered when I catch her? If "no" exactly what fraction of the trip have I covered when my sister gets home?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
My sister can walk from school to home in 40 minutes.
I can walk from school to home in 30 minutes.
Today I stayed for some extra help, and my sister was already 2/5 of the way home when I started.
If I walk at my usual speed, can I catch my sister before she gets home?
If "yes" exactly what fraction of the trip have we covered when I catch her?
If "no" exactly what fraction of the trip have I covered when my sister gets home?
:
Let d = distance from home to school
then
d%2F30 = .033d, your speed walking home
and
d%2F40 = .025d, sister's speed walking home
:
When you start, sister is 2/5 the way which means:
she has 3%2F5d or .6d to go
:
Find her time to get home: %28.6d%29%2F.025d = 24 min to get home
then
We know it takes you 30 min to get home so she will beat you home by 6 min
and
You will have covered 24%2F30 = 4%2F5 of the way home then