C) 250 is the right answer
36 3/4 = 36.75
36 3/8 = 36.375
37 1/2 = 37.5
36 5/8 = 36.625
(36.75 + 36.375 + 37.5 + z) / 4 = 36.625
(110.625 + z) / 4 = 36.625
110.625 + z = 36.625 * 4
110.625 + z = 146.5
z = 146.5 - 110.625
z = 35.875 or 35 7/8 <===
276 is the answer because 460 times .6 = 276
circurference of gear = 2πr
= 2π(10)
= 62.83185307 inches
= 62.83 inches (4sf)
You can only solve this by having the same base on each side. So to change 1/27, you can use 3^-3, which is then multiplied through. So the equation is:
4x-5=-3(2x+10)
4x-5=-6x-30
10x=-25
x=-2.5