7/8 of an hour is 52.5 minutes. 3/10 of 52.5 minutes is 15.75 minutes. They spent 15.75 minutes warming up and cooling down.
Answer:
81
Step-by-step explanation:
Its a perfect square and 27*3=81
The dimensions of the rectangle given are
length = 14 meters
Width = 8 meters
The perimeter of the rectangle is given by the sum of its sides
The rectangle has to opposite sides of 14 meters and two opposite sides of 8 meters
Hence adding up the 4 sides we get

Hence option B is the right answer
We know that there are (4^9)^5 ⋅ 4^0 at the library, so we just need to simplify this to get the answer.
(4^9)^5 ⋅ 4^0
=(4^9)^5×1
=(4^9)^5
=4^9×5
=4^45. As a result, the total number of books at the library is 4^45 books at the library or B is the final answer. Hope it help!