The correct option is B 56
∵ 1 is a zero,
p(1)=0
⇒ 12−a+b=0
⇒ a−b=1......eq (i)
Also,
∵ 7 is also a zero,
p(7)=0
⇒ 72−(7)a+b=0
⇒ 7a−b=49......eq (ii)
Subtracting (i) from (ii), we have
7a−b−a+b=48
⇒ 6a=48
⇒ a=8
Substituting a=8 in eq (i), we have
8−b=1
⇒ b=7
∴ ab=(8)(7)=56