21.3 is the correct answer.
I belive it is the second option!
Solutions
<span>To solve the problem our first step is to find the prime factorization of each number. </span>
4 = 2²
<span>5 = 5 </span>
<span>6 = 2 x 3
</span>
Calculations
<span>LCM = 2² x 3 x 5 = 60 </span>
You can ise repeated reasonings
