At 09 30, Betty left Town S and cycled towards Town T. Dana left Town S and cycled towards Town T at 09 45. Dana's cycling speed was 4 km/h faster than Betty. At 11 30, Dana caught up with Betty. Find the cycling speed of each cyclist.
- Betty
- Dana
(a)
Duration that Dana cycled from 09 45 to 11 30
= 1
4560 = 1
34 h
Distance that Dana cycled more than Betty
= 1
34 x 4
= 7 km
However, since Betty left 15 minutes earlier than Dana and Dana caught up with Betty, it means that Betty has cycled 7 km in 15 min.
1 h = 60 min
15 min = 15 ÷ 60 =
14 h
Betty's cycling speed
= 7 ÷
14 = 7 x
41 = 28 km/h
(b)
Dana's cycling speed
= 28 + 4
= 32 km/h
Answer(s): (a) 28 km/h ; (b) 32 km/h
