Solve each problem involving direct or inverse variation. 13) Ifx varies directly as y, and x = 27 when y = 6, find x when y = 2. 14) If y varies inversely as x, and y = 23 when x = 8, find y when x = 4. 15) If z varies directly as x, and z = 30 when x = 8, find z when x = 4. 16) If y varies inversely as x, and y = 14 when x = 8, find y when x = 7. 17) If d varies directly as t, and d = 150 when t= 3, find d when t = 5. 18) If y varies directly as x, and y = 6 when x = 10, find x when y = 18. 19) If x varies inversely as y, and x = 3 when y = 8, find y when x = 4. 20) If z varies inversely as x, and z = 9 when x 2 5 find z when x 3' 4