The first number but it doesn't really matter.
Answer:
7 1/2
Step-by-step explanation:
If it drops 2 per hour, and you need it to drop 15, divide 15 by 2 and you’ll get 7.5 or 7 1/2
15+5•y/2
15+5•4 / 2
15+20 / 2
15+10
=25
So basically you just need to do the Pythagorean theorem to find the sides of the shaded rectangle, with c being the length of the side.
Small side:
2^2 + 6^2 = c^2
4 + 36 = c^2
40 = c^2
C is similar to 6.32456
Long side:
12^2 + 4^2 = c^2
144 + 16 = c^2
160=c^2
C is similar to 12.64911
And then you just multiply!