You know that every 10 minutes the oil moves 25 meters so and in 1 hour there are 60 minutes the equation is 60/10(25) and then you solve
The answer is 150 meters squared
Something happened when you copy and pasted the question, was it important to the question?
$20 bought 16 songs
Therefore each song costs $20/16 = $5/4 = $1.25
So:
2 songs would cost 2 * $1.25
3 songs would cost 3 * $1.25
...
x songs would cost x * $1.25
Since Renata started with $20, then her balance (y) after buying x songs would be:
y = 20 - 1.25*x