A natural number has prime factorization given by n = 2 x 3 y 5 z , where y and z are such that y + z = 5…

A natural number has prime factorization given by n=2x3y5z, where y and z are such that y+z=5 and y-1+z-1=56,y>z. Then the number of odd divisors of n, including 1, is:
  1. 12
  2. 6
  3. 11
  4. 6x

Solution

y+z=5

1y+1z=56  y>z

y=3,z=2

n=2x.33.52=2.2.23.3.35.5

For calculating the odd divisor ofn=2x3y5z, x must be 0.

Hence, Number of odd divisors =3+1×2+1=4×3=12.

Asked in: JEE Main 2021 (26 Feb Shift 2)

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