Required length = H.C.F. of 495 cm, 900 cm and 1665 cm. 495 = 3² x 5 x 11, 900 = 2² x 3² x 5², 1665 = 3² x 5 x 37. H.C.F. = 32 x 5 = 45. Hence, required length = 45 cm.
L.C.M. of 5, 6, 7, 8 = 840.Required number is of the form 840k + 3Least value of k for which (840k + 3) is divisible by 9 is k = 2.Required number = (840 x 2 + 3) = 1683.
EXAMIANS