SOLUTION: Alex and Bert Agreed to meet on the highway connecting their hometowns, which are 120 km apart. Alex drives at 45 kph, while bert drives at 35 kph. In how many hours will they meet

Algebra.Com
Question 1119548: Alex and Bert Agreed to meet on the highway connecting their hometowns, which are 120 km apart. Alex drives at 45 kph, while bert drives at 35 kph. In how many hours will they meet?
Found 3 solutions by Theo, MathTherapy, Alan3354:
Answer by Theo(13342)   (Show Source): You can put this solution on YOUR website!
they are 120 km apart.

alex drives at 45 kmph.
bert drives at 35 kmph.

if alex drives x km, then they will meet when bert drives (120 - x) km.

they will both have been driving the same amount of time.

the formula to use is R * T = D

R is the rate in kilometers per hour.
T is the time in hours.
D is the distance in kilometers.

for alex, the formula becomes 45 * T = x
for bert, the formula becomes 35 * T 120 - x

these 2 equations need to be solved simultaneously.

one way to solve is as follows:

rearrange the terms so all the variables are on one side of the equations and all the constants are on the other side.

the equations become:

45 * T - x = 0
35 * T + x = 120

add the second equation to the first to get:

80 * T = 120

solve for T to get T = 120/80 = 12/8 = 1.5 hours.

they both travel for 1.5 hours.

in that 1.5 hours, alex travels 45 * 1.5 = 67.5 kilometers.

in the same 1.5 hours, bert travels 35 * 1.5 = 52.5 kilometers.

the sum of 67.5 and 52.5 = 120 kilometers in total.

if alex started at the 0 kilometer mark, then he traveled 0 + 67.5 kilometers to the 67.5 kilometer mark in 1.5 hours.

if bert started at the 120 kilometer mark, then he traveled 120 - 52.5 kilometers to the 67.5 kilometer mark in 1.5 hours.

they met at the 67.5 kilometer mark.

the solution is that they will meet in 1.5 hours.


Answer by MathTherapy(10552)   (Show Source): You can put this solution on YOUR website!
Alex and Bert Agreed to meet on the highway connecting their hometowns, which are 120 km apart. Alex drives at 45 kph, while bert drives at 35 kph. In how many hours will they meet?
It needs to be pointed out that they left their respective destinations at the SAME TIME. It's safe to assume that 

they did, and if so, and with the time they took to meet being T, we get the following DISTANCE equation: 45T + 35T = 120.

Solve this for the time it'll take them to meet. 

Answer by Alan3354(69443)   (Show Source): You can put this solution on YOUR website!
 You have to state when each left. 

RELATED QUESTIONS


Alex and Bert agreed to meet on the highway connecting their hometowns, which are 120 km... (answered by JulietG)

Dear Tutor, I hope you can help me with these problems. Please know that I've tried them... (answered by richwmiller)

URGENT!

1. Mr. Honda anf Mr. Toyota arrange to meet on the highway connecting their... (answered by ankor@dixie-net.com)

Alex the geologist is in the desert, 10 km from the nearest point N on a long, straight... (answered by josgarithmetic)

Andy lives in Houston and is 350 miles away from Sidh, who lives in New Orleans. They... (answered by macston,ikleyn)

John and Mike have been friends since school but havent seen eachother in many years, so... (answered by ptaylor)

John leaves his house at 10 am and drives east at 50 mph.  Mike leaves his house at the... (answered by richwmiller)

John and Alex start driving home from a party. Jon drives 9 miles north and Alex drives... (answered by Alan3354,MathTherapy)

I just need to know what kind of formula I need to solve a problem like this:
"Alex and... (answered by josmiceli)