Answer:
2.5 one decimal rounding off means to make it to one decimal place.the no is 24.9652 if you want to round of then you have to put decimal after 2 only then it will be one decimal place .this is because when we see a number after the point greater than 5 then we add 1 to the right side .now if we add 1 to the right side of 24.9652 by rounding off and making it to one decimal place then it will be 2.5.
2(5-n) can be an expression of "twice the difference of 5 and n".
The answer is 16 if you solve it, because the square root of 64 is 8 and 2 * 8 = 16
