A belt drive system consists of the wheels A, B and C, which rotate smoothly. Wheel
B turns 4 full rounds when wheel A turns 5 full rounds. Wheel B turns 6 full rounds when
wheel C turns 7 full rounds. Find the perimeter of wheel A if the perimeter of wheel C is 30cm.
(A) 27 cm
(B) 28 cm
(C) 29 cm
(D) 30 cm
(E) 31 cm

Thompson and thompson is a steel bolts manufacturing company. their current steel bolts have a mean diameter of 127 millimeters, and a variance of 36. if a random sample of 35 steel bolts is selected, what is the probability that the sample mean would differ from the population mean by greater than 0.5 millimeters? round your answer to four decimal places.