Question

Sum of first three terms of an ap is 30, find the numbers while their product is 1620

Answer 1

let the no. be a, a+ d, a-d.
a + a + d+ a-d =30
3a=30
a=30/3
a=10
a.a+ d.a-d =1620
10.10+d.10-d=1620
10.10^2-d^2=1620
10. (100-d^2)=1620
1000-10d^2=1620
-10d^2=1620-1000
-10d^2=620