in a car race, car number three averages 140km/h and car number five averages 5 % greater than car number 3. if one lap of the track is 8 km, how many laps around the track will car number 3 go before being passed by car number 5?
2007-10-23 04:31:16 · 1 answers · asked by Kalluto~ 2 in Science & Mathematics ➔ Mathematics
please show ur work
2007-10-23 04:31:50 · update #1
Each time car three completes a lap (8 km), car 5 will have gone 5% farther around the track. The question is when will they have gained 100% of a lap on the first car.
100% / 5% = 20
So it will be 20 laps. All the rest of the information is extraneous.
Just to double-check our answer:
The slower car will go 20 laps (160 km) at 140 km/h. This will take 1 1/7 hours (160/140).
The faster car will go 21 laps (168 km) at 147 km/h (5% faster). This will take 1 1/7 hours (168/147).
So the answer is 20 laps.
2007-10-23 04:42:42 · answer #1 · answered by Puzzling 7 · 1⤊ 0⤋