By Euclid’s division lemma -

x = bq + r ….(1)

where q is the quotient,

r is the remainder

and b is the divisor.

According to the question, x = 1365, r = 32, q = 31, b = ?.

Putting the values in equation(1) -

∴ 1365 = b(31) + 32

⇒ 31b = 1333

⇒ b = 43