That's an equal to or less then sign so 10 or anything below should be correct
The volume of the original cylinder is
... V = π·r²·h
For r=1 and h=1, this is
... V = π·1²·1 = π
For the new cylinder, the volume is 1.089 times that amount.
... V = 1.089π = π·1.1²·(1-k)
... 1.089/1.21 = 1-k
... k = 1 - 1.089/1.21 = 1 - 0.9 = 0.1 = 10%
The appropriate choice is (B) 10.
No, there is no 'greatest integer'. That is because positive numbers can go up tp infinite, and we do not know where numbers stop.
However, there is a negative greatest integer because the ones that's closes to zero is -1.
Tanα=5/12
α=arctan(5/12)°
α≈22.62° (to nearest hundredth of a degree)