Answers

2015-12-05T13:09:15+05:30
Let the AP is (a-d), a, (a+d)
(a-d)+a+(a+d) =21
3a=21
a=7
(a-d)×a×(a+d)=231
(a×a-d×d) ×a=231
(7×7-d×d)×7=231
(7×7-d×d)=231÷7
(7×7-d×d)=33
d×d=49-33
d×d=16
d=4
Hence, the A. P. is 3, 7, 11.
0
2015-12-05T14:33:32+05:30
Let the number be (a-d), a, (a+d)
(a-d)+a+(a+d)=21
a-d+a+a+d=21
3a=21
a=7
(a-d)×a×(a+d)=231
(a²-d²)×7=231
a²-d²=33
7²-d²=33
49-d²=33
d²=49-33
d²=16
d=4
numbers = 3,7,11
0