A k-almost prime number is defined as a positive integer with exactly k prime factors that are not necessarily distinct. The third smallest 4-almost prime number, less the fourth smallest 3-almost prime number is Choose the correct choice from the following answers
A) 6
B) 8
C) 16
D) 24
E) 28
Solution: 3-almost prime numbers : 8(as 8 = 2*2*2) , 12 (2*2*3) , 18 (2*3*3) , 20 (2*2*5)....   4-almost prime numbers : 16(as 8 = 2*2*2*2) , 24 (2*2*2*3) , 36 (2*2*3*3)...   The third smallest 4-almost prime number, less the fourth smallest 3-almost prime number = 36-20= 
<gadget id="calculator">36-20</gadget>
<output>16</output>
16.   Option 16.
<result>C</result>
A k-almost prime number is defined as a positive integer with exactly k prime factors that are not necessarily distinct. The third smallest 4-almost prime number, less the fourth smallest 3-almost prime number is