The answer would be three
ANSWER:
d = 15
The swimmer swam 48 kilometres in 15 days.
STEP-BY-STEP EXPLANATION:
Let d = total no. of days the swimmer swam
Total no. of kilometres swam = 48
Average no. of kilometres swam daily = 3.2
THEREFORE:
3.2d = 48
d = 48 / 3.2
d = 15
1/3 of 6=2(4 left)
3/8 of 4=1 1/2
1 1/2 yards left
<h2>
Hello!</h2>
The answer is:
The ball will hit the ground after 
<h2>
Why?</h2>
Since we are given a quadratic function, we can calculate the roots (zeroes) using the quadratic formula. We must take into consideration that we are talking about time, it means that we should only consider positive values.
So,

We are given the function:

Where,

Then, substituting it into the quadratic equation, we have:

Since negative time does not exists, the ball will hit the ground after:

Have a nice day!
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