Please help on this question!!

Which radical expression is a rational number? a. √ 360 b. √ 644 c. √ 225 d. √ 122

The height of a birch tree, f(x), in inches, after x months is shown in the graph below. how much does the birch tree grow per month, and what will be the height of the birch tree after 10 months? a. the birch tree grows 1 inch per month. the height of the birch tree will be 16 inches after 10 months. b. the birch tree grows 2 inches per month. the height of the birch tree will be 26 inches after 10 months. c. the birch tree grows 3 inches per month. the height of the birch tree will be 36 inches after 10 months. d. the birch tree grows 2 inches per month. the height of the birch tree will be 24 inches after 10 months.

The mean average cost of standard room per night at a hostel is ? 20.60. therefore, how much does a standard room cost per night at night-time rest days?