A car travels 30km at a uniform speed of 40km/hr and the next at 30km at a uniform speed of 20km/hr. Find the time taken?

1 Answer
Mar 25, 2018

#"2.25 hour"#

Explanation:

#"Time" = "Distance"/"Speed"#

Time taken to travel first #"30 km"#

#t_1 = "30 km"/"40 km/hr" = 3/4\ "hr"#

Time taken to travel next #"30 km"#

#t_2 = "30 km"/"20 km/hr" = 3/2\ "hr"#

Total time taken

#t = t_1 + t_2#

#t = 3/4\ "hr" + 3/2\ "hr"#

#t = 3/4\ "hr" + (3/2 × 2/2)\ "hr"#

#t = 3/4\ "hr" + 6/4\ "hr"#

#t = (3 + 6)/4\ "hr" = 9/4\ "hr" = color(blue)"2.25 hr"#