If there are 8 groups of 65 students, that means they can seat 8*65 students total. 520 students
Rectangular prism Area=2(wl+hl+hw) in this case, the length (l) is 9m, the width (w) is 8m, the height (h) is 9m. Just plug everything into the formula: 2(8*9+9*9+9*8)=450m^3. Hopefully It helped. Have a good day.
B. 2 time 2 is 4 , 4 times two is 8, 8 times five is 40
Total thickness of the stack of cards = 3/4 inch or 0.75 inch
In a full stack of cards, there are 52 cards.
Hence, the thickness of 52 cards = 0.75 inch.
To find the thickness of one card, we divide the total thickness with the total number of cards.
Thickness of one card = 
1 inch = 2.54 cm
0.014423 inch is approximately equal to 0.34 cm.
Answer = 0.34 cm
Here's one way to do it.
AB ≅ AC . . . . . . . . . . given
∠BAY ≅ ∠CAY . . . . given
AY ≅ AY . . . . . . . . . . reflexive property
ΔBAY ≅ ΔCAY . . . .. SAS congruence
XY ≅ XY . . . . . . . . . . reflexive property
∠AYB ≅ ∠AYC . . . . CPCTC
BY ≅ CY . . . . . . . . . . CPCTC
ΔXYB ≅ ΔXYC . . . .. SAS congruence
Therefore ...
∠XCY ≅ ∠XBY . . . . CPCTC