Three numbers are in AP. If their sum is 27 and their product is 648, find the numbers.

To Find: The three numbers which are in AP.


Given: Sum and product of three numbers are 27 and 648 respectively.


Let required number be (a - d), (a), (a + d). Then,


(a - d) + a + (a + d) = 27 3a = 27 a = 9


Thus, the numbers are (9 - d), 9 and (9 + d).


But their product is 648.


(9 - d) × 9(9 + d)= 648


(9 - d)(9 + d)= 72


81 – d2 = 72 d2 = 9 d =3


When d=3 numbers are 6, 9, 12


When d= (3) numbers are 12, 9, 6


So, Numbers are 6, 9, 12 or 12, 9, 6.


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