Question

The smallest natural number which is divisible by 33, 72, 11 and 18 is:

• A. 839
• B. 696
• C. 792
• D. 881

Answer 1

Answer:

C. 792

We need the LCM of 33, 72, 11, and 18.

Prime factorization

• $(33 = 3 \times 11)$

• $(72 = 2^3 \times 3^2)$

• $(11 = 11)$

• $(18 = 2 \times 3^2)$

  Take highest powers

• $(2^3) (from 72)$

• $(3^2) (from 72 or 18)$

• $(11) (from 33 or 11)$

  Multiply

$\text{LCM} = 2^3 \times 3^2 \times 11$
$= 8 \times 9 \times 11$
$= 72 \times 11$
= 792