Let:
v = Olga's speed
t = the time Anna spent going to school (3 km/hour)
t/2 = the time Anna spent running back home with speed of 6 km/hour
So, t + t/2 = 3t/2 is the total time
In the meantime distance = speed*time and the both made the same distance we can put it as:
3t + 6*(t/2) = (3t/2)*v
6t = (3/2)tv divide both sides by t
(3/2)v = 6
v = 2*6/3
v = 4 km/hour
Olga's speed was 4 km/hour.
Answer:
15 and 108
Step-by-step explanation:
3*(30-25)=3*5=15
4*(12+15)=4*27=108
Answer:
39 ft²
Step-by-step explanation:
Area of a triangle = 1/2bh
Let:
base = b = 4 ft
height = h = 3 ft
Solve for the area of the triangle:
A = 1/2(4)(3)
A = 2 * 3
A = 6 ft²
Area of a rectangle = bh
Let:
base = b = 9 ft
height = h = 5 ft
Solve for the area of the rectangle:
A = (9)(5)
A = 9 * 5
A = 45 ft²
Subtract the area of the triangle from the area of the rectangle:
45 - 6 = 39 ft²
39 ft² is your answer.
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