Question

Juan roller skated for 2 hours 40 minutes with a constant speed of 18 m/h and then for another 1 hour 50 minutes with a constant speed of 24 m/h. What distance did he go?

Answer 1

Answer: 136 m

Explanation:

For first interval,

Time = 2 hours 40 minutes =
`2+(40)/(60)\text{ hours}\ [\text{1 hour = 60 minutes}]`

`=2+(2)/(3)=(8)/(3)\ \text{hours}`

Speed = 18 m/h

Distance =
`(8)/(3)*18=48\ m`[Formula : Distance=Speed x time]

For second interval,

Time = 1 hour 50 minutes =
`1+(50)/(60)\text{ hours}\ [\text{1 hour = 60 minutes}]`

`=1+(5)/(6)=(11)/(3)\ \text{hours}`

Speed = 24 m/h

Distance =
`(11)/(3)*24=88\ m`

Total distance = 48 m +88 m = 136 m

Hence, he went 136 m.