You ARE going to be 79 anos because i subtracted 2016 ands 1937 and got 79
<em>So</em><em> </em><em>the</em><em> </em><em>right</em><em> </em><em>answer</em><em> </em><em>is</em><em> </em><em>of</em><em> </em><em>option</em><em> </em><em>B</em><em>.</em>
<em>Look</em><em> </em><em>at</em><em> </em><em>the</em><em> </em><em>attached</em><em> </em><em>picture</em><em>⤴</em>
<em>Hope</em><em> </em><em>it</em><em> </em><em>will</em><em> </em><em>help</em><em> </em><em>u</em><em>.</em><em>.</em><em>.</em>
Use the trigonometric function.
![\sin30^o=\dfrac{x}{20}\\\\\sin30^o=\dfrac{1}{2}\\\\\dfrac{x}{20}=\dfrac{1}{2}\ \ \ |\cdot20\\\\x=10](https://tex.z-dn.net/?f=%5Csin30%5Eo%3D%5Cdfrac%7Bx%7D%7B20%7D%5C%5C%5C%5C%5Csin30%5Eo%3D%5Cdfrac%7B1%7D%7B2%7D%5C%5C%5C%5C%5Cdfrac%7Bx%7D%7B20%7D%3D%5Cdfrac%7B1%7D%7B2%7D%5C%20%5C%20%5C%20%7C%5Ccdot20%5C%5C%5C%5Cx%3D10)
I am assuming that the cost of an oil change already includes the mark-up.
So, 18 is 175%. 18 ÷ 1.75 = 10.29 is the original cost.
10.29 * 3/4 = 30.87/4 = 7.71 mark-up
10.29 + 7.71 = 18
Or if 18 is the basis of the mark-up, then,
18 * 3/4 = 54/4 = 13.50 mark-up
18 + 13.50 = 31.50 new cost of an oil change