Final answer:
The least common denominator (LCD) of 1/5 and 2/3 is 15 (C).
Step-by-step explanation:
The least common denominator (LCD) of two fractions is the smallest number that both denominators can evenly divide into. To find the LCD of 1/5 and 2/3, we need to find the smallest multiple that both 5 and 3 can divide into. The multiples of 5 are 5, 10, 15, 20, ... and the multiples of 3 are 3, 6, 9, 12, .... The least common multiple (LCM) of 5 and 3 is 15.
The multiples of 5 are 5, 10, 15, 20,... and the multiples of 3 are 3, 6, 9, 12, 15,... As we can see, 15 is the first number that appears in both lists, so the least common denominator is 15.
However, looking at the answer choices provided: A) 5, B) 3, C) 15, and D) 10 - we can see that 15 is listed and is in fact the correct answer. Ultimately, the LCD of 1/5 and 2/3 is option C) 15.
Therefore, the least common denominator of 1/5 and 2/3 is 15 (C).