Answer:
Sam sokey 0.5 hours biking and 3.5 hours walking
Step-by-step explanation:
Here, we want to know the number of hours spent walking and biking
Mathematically; distance = speed * time
Let the number of hours spent walking be x and the number of hours spent biking be y
Mathematically;
x + y = 3 •••(i)
distance spent walking = 4 * x = 4x miles
distance spent biking = 12 * y = 12y miles
4x + 12y = 20
divide through by 2
2x + 6y = 10 ••••••(ii)
From i , x = 4-y
Substitute this into ii
2(4-y) + 6y = 10
8 - 2y + 6y = 10
8 + 4y = 10
4y = 10-8
4y = 2
y = 2/4 = 0.5 hours
The number of hours spent walking = 4-0.5 = 3.5 hours
