SOLUTION: 1. The round trip from home to work takes 1.5 hrs. What is the distance to work if the trip going to it was done at 7 miles per hour and the return trip at 12 miles per hour? Verif

Question 631153: 1. The round trip from home to work takes 1.5 hrs. What is the distance to work if the trip going to it was done at 7 miles per hour and the return trip at 12 miles per hour? Verify.
______________________________________�
2. Bob rows his boat at 50 m/min going downstream and 20 m/min going upstream. How far down the river should he go so that he can return at 3:05pm; from where he started, if he left at 10:45 am? Verify.

If you can help me with these questions it'll be great! I could not find any ways to solve them. Thanks!
Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website!
1. The round trip from home to work takes 1.5 hrs.
What is the distance to work if the trip going to it was done at 7 miles per
hour and the return trip at 12 miles per hour? Verify.
let d = distance to work
Write a time equation: time = dist/speed
:
to work time + return time = 1.5 hrs
+ = 1.5
multiply by 84 to get rid of the denominators
84* + 84* = 84*1.5
cancel the denominators
12d + 7d = 126
19d = 126
d = 126/19
d = 6.63 mi dist to work
:
verify by finding the times each way
6.63/7 = .947 hrs
6.63/12= .553 hrs
----------------
total time: 1.5 hrs
:
:
2. Bob rows his boat at 50 m/min going downstream and 20 m/min going upstream.
How far down the river should he go so that he can return at 3:05pm; from
where he started, if he left at 10:45 am? Verify.
:
Find the number of minutes from 10:45 am to 3:05 pm
14:65 - 10:45 = 4:20; 4(60) + 20 = 260 minutes downstream and back
:
let d = the one way distance downstream
:
Write a time equation: time = dist/speed
:
Time downstream + time back = 260 min
+ = 260
multiply by 100 to get rid of the denominators
2d + 5d = 260 * 100
7d = 26000
d = 26000/7
d = 3,714.3 meters downstream (3.7 km)
:
:
Verify this by finding the time each way
3714.3/50 = 74.3 min
3714.3/20 = 185.7 min
-----------------------
total time: 260 min

RELATED QUESTIONS
You have 20-mile commute into work. Since you leave early, the trip going to work is... (answered by josmiceli)

You have a 15-mile commute into work. Since you leave very early, the trip... (answered by jorel1380)

from home travel 60 mph to a city, go back home at 50 mph. round trip takes 5 hrs. how... (answered by CubeyThePenguin)

bob's work is 40 miles away from his home. His average mph to work is 20. his average mph (answered by ankor@dixie-net.com,MathTherapy)

You have a 25-mile commute into work. Since you leave very early, the trip... (answered by addingup,MathTherapy,josgarithmetic)

Anayet Is drive me to work from home and realizes he left his wallet at home when he is... (answered by greenestamps)

A motorcycle breaks down and the rider must walk the rest of the way to work. The... (answered by stanbon)

If Amy drove from home to work at 30km per hours, and then drove from work back home... (answered by Alan3354)

Each day Bob walks back and forth to work from his home following the same path. He... (answered by josmiceli)