Question

Find three numbers in A.P. whose sum is 21 and their

product is ​

Answer 1

Answer:

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)=

7

231

(7×7−d×d)=33

d×d=49−33

d×d=16

d=4

Hence, the A.P is 3,7,11