Answer:
Answer:
12 km/h and 10 km/h
Explanation:
Let the speed of Masha = s, speed of Dasha = d
Distance = 20 km
Time difference = 20 min = 1/3 hr
Speed difference = 2 km/h
As per above info we get following equations:
s = d + 2
20/s + 1/3 = 20/d
Substitute s and solve for d:
20/(d + 2) + 1/3 = 20/d
Get rid of fraction by multiplying all terms by 3d(d + 2):
60d + d(d + 2) = 60(d + 2)
60d + d² + 2d = 60d + 120
d² + 2d = 120
d² + 2d + 1 = 121
(d + 1)² = 11²
d + 1 = 11
d = 10
Find s:
s = 10 + 2 = 12
The answer is
Masha's speed 12 km/h and Dasha's speed 10 km/h