The answer is choice A, a 3.5% increase.
12/15 = 80%
13/17 = 76.47%
80% - 76.47% = 3.5%
All that are true:
sin(C) = square root 3/2
tan(C) = square root 3
sin (B) = 1/2
Answer:
First find the area 72*63
A=4536
Then find the area 12*12
A=144
Then divide 4536/144
You would need 31.5 12 by 12in covers to decorate the rectangular region
As for the 6 by 6
You would need 126 album covers
As for the 9 by 9
You would need 51 covers
And as for the 15 by 15
You would need 20.6 covers
48/70 = 24/35
24/35 = 0.6857
= 68.57%