Three numbers are in A.P. If the sum of these numbers be 27 and the product 648, find the numbers.
Let the three numbers be a – d, a, a + d
a – d + a + a + d = 27
3a = 27
a = 9
According to question,
(a – d) (a) (a + d) = 648
(a2 – d2) (a) = 648
(92 – d2) 9 = 648
(81 – d2) = 72
d2 = 9
d = 3
Therefore, a – d = 9 – 3 = 6
A + d = 9 + 3 = 12