UPSC CDS I 2019 Math Paper

Sum of roots = p + q
=

b

a

=15.......(1)
Product of roots =pq=

c

a

=r....(2)
Also,
p−q=1...(3)
Adding (1) and (3), we get: p = 8
Putting p = 8 in equation (3), we get: q = 7
Putting the values of p and q in (2), we get:r=8×7=56