Question

Find three consecutive terms which are in ap whose sum is 21 and product is 231

Answer 1

Answer:

Step-by-step explanation:

Let the AP be x-d,x,x+d

Sum of AP=21=3x

x=3 therefore first term of AP is 3

And product of these AP term is given 231

So common difference be d=+4,-4

So your AP 3,7,11

or 11,7,3

Answer 2

Let the no. be

(a - d) , a , (a + d)

Given,

a - d + a + a + d = 21

So,

a is 7.....

Also,

(a - d) * a * (a + d) = 231

(7 - d) * 7 * (7 + d) = 231

343 - 7d^2 = 231

So,

d^2 = 16

Hence,

d is either 4 or -4......

So,

No. are

1) (7 - 4) , 7 , (7 + 4)

3 , 7 , 11

2) ( 7 + 4) , 7 , (7 - 4)

11 , 7 , 3