The number of intergral divisors of 720 is

a) 15 b) 20 c) 25 d) 30

720=2⁴ * 3² * 5¹

so, the number of integral divisors of 720 are (4+1) * (2+1) * (1+1) = 5*3*2 = 30

Ans: d) 30