Question

Find three numbers in an
a.p. whose sum i s 15 and product 80

Answer 1

Three number in AP are (a-d), (a), (a+d)

a-d+a+a+d=15

3a=15

a =5

putting value of a in the numbers (a-d), (a), (a+d) we get 5-d, 5 , 5+d

(5-d)*5*(5+d)=80

    (5-d)(5+d)=16

         (5)2-d2=16

           25-d2=16

                d2=9

                 d=3 OR -3

in case 1,d=3

the numbers are 2 ,5 ,8  

in case 2, d=-3

the numbers are 8 ,5 ,2

hope this helps !!!