Elizabeth was helping her sister make their mother a necklace. They had 3 6/8 cups of beads. When they finished, they had 1 2/4 cups left. How many cups of beads did Elizabeth and her sister use?%C2%A0 Write your answer in simplest form.

Answer 1

To find the amount of beads that Elizabeth and her sister used, we need to subtract the amount left from the amount they started with.

We can rewrite 3 6/8 as an improper fraction by multiplying the whole number by the denominator and adding the numerator:

= (3 * 8) + 6/8 = 24/8 + 6/8 = 30/8

So, they started with 30/8 cups of beads.

To find the amount used, we subtract the amount left from the amount they started with:

30/8 - 1 2/4 = 30/8 - 6/4

We need to make the denominators the same, so we rewrite 30/8 as 30/8 * 2/2 = 60/16.

60/16 - 6/4 = 60/16 - 24/16 = 36/16.

We can simplify this fraction by dividing the numerator and denominator by their greatest common divisor, which is 4:

= (36/4) / (16/4) = 9/4.

Therefore, Elizabeth and her sister used 9/4 cups of beads or 2 1/4 cups of beads.