Question

What is the LCD for 11/21 and 31/45?
A.) 945
B.)315
C.)66
D.)105

Answer 1

The LCD is the Least common multiple of 21 and 45, which is the product of the highest occurring primes of the numbers prime factorizations.

21=3*7, 45=3*3*5 so the LCM of 21 and 45 is 3*3*5*7=315

So the LCD is 315

Answer 2

B) 315 is the LCD FOR 11/21 AND 31/45