time rough+timesmooth= 50/24
sum of distances equals 50km or
time rough= 25/18 hrs
distance rough= 25/18 * 12=50/3 km
check all that.
Let the distance on good road be x km
then distance on rough road is 50-x km
time on good road = x/30
time on rough road = (50-x)/12
total time = x/30 + (50-x)/12
= (2x + 250 - 5x)/60
= (250 - 3x)/60
but total time = 50/24
so (250-3x)/60 = 50/24
3000 = 6000 - 72x
72x = 3000
x = 3000/72 = 125/3 or 41 .67 km
so 42.67 km were good road and
50 - 41.7 or 8.3 km were under repair.
check: total time = 50/24 = 2.083 hrs
time on good road = 41.67/30 = 1.389
time on rought road = 8.3/12 = .692
total time = 2.081 , close enough allowing for round-off
all checks out
Answer this Question
Algebra - How do you work this out? Going downstream a tugboat averages 17 kph. ...
Math - a bus travels 240 kilometers at 60 kph and then returns at 40 kph.. what ...
math - integers - 3. Arlan and Bryan started driving from the same place. Arlan ...
Math - what value of m will make 4x-7y=5 and 9x+my=3 parallel? a car leaves town...
Calculus,reaction rates - A car starting at 12:00 noon travels west at a speed ...
math - it takes carissa five hours and thirty minutes to drive 440km to her ...
Trig - You and a friend are rowing a boat 8.5 KPH heading north. A cross current...
science - What is the velocity of a car traveling from the east coast to the ...
physics - an automobile travels at a uniform speed of 88 kph. how many metres ...
math - How long does it take to travel 84.2km at 80 kph