What is the lcd for fractions

5/7 and 1/21. ?

For the denominators (7, 21) the least common multiple is 21.

Therefore, the least common denominator (LCD) is 21.

Rewriting the original inputs as equivalent fractions with the LCD:
15/21, 1/21

If there are four friends then each would get, 1.25 or 1 1/4. so this is how i solved 5 ÷ 4 = 1.25 . hope this ; )