Which of the following mathematical methods returns only an integer?

1. Math.ceil(n)
2. Math.sqrt(n)
3. Math.floor(n)
4. Math.round(n)

The output of the statement Math.ceil.(89.9) + Math.floor(90.5) is:

1. 0.0
2. 180
3. 180.0
4. 180.4

A Student executes the given program segment and it results in 1.0, irrespective of the value of n. State the type of the error, write the correct statement:

void solve(int n) 
{ double power=Math.pow(n, 2/3); 
System.out.println(power); 
}