Answer: 14.0 km/h
Explanation:
First find the distance that both Ade and Kali travelled. Use the time and speed of Ade to find this out:
Distance = Speed * Time
= 15 * 2
= 30 km
Kali took 2 hours 15 minutes to travel 30km. Her speed is therefore:
= Distance / Time
Convert the time to decimal:
Mixed fraction = 2¹⁵/₆₀
= 2¹/₄
Decimal = 2.15 hours
Average speed = 30 / 2.15
= 13.95
= 14.0 km/h