SOLUTION: A 5-inch breadstick is broken into 3 pieces. One piece is 2 1/2 inches long; the second is 1 3/4 inches long. how long is the third piece?

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: A 5-inch breadstick is broken into 3 pieces. One piece is 2 1/2 inches long; the second is 1 3/4 inches long. how long is the third piece?      Log On


   



Question 204272: A 5-inch breadstick is broken into 3 pieces. One piece is 2 1/2 inches long; the second is 1 3/4 inches long. how long is the third piece?
Answer by PRMath(133) About Me  (Show Source):
You can put this solution on YOUR website!
The first piece is 21%2F2
The 2nd is 13%2F4

Let's add those by first changing your two MIXED fractions to IMPROPER fractions.

Take 2 1%2F2 and multiply the 2 in the denominator times the 2 in the fraction. Now add 1 from the numerator. (2 * 2) + 1 = 5
Put the 5 in the numerator and keep the 2 in the denominator and you get: 5%2F2

Therefore: 2 1%2F2 = 5%2F2

Let's now take 1 3%2F4 and change it to an improper fraction by multiplying the 4 in the denominator times the 1. Now add 3 from the numerator. (4 * 1) + 3 = 7.
Put the 7 in the numerator and keep the 4 in the denominator and you get: 7%2F4

Therefore: 1 3%2F4 = 7%2F4


These two fractions represent the TOTAL AMOUNT of what is taken from the WHOLE 5 inch loaf so far. What is the TOTAL amount? Let's add the two fractions....

5%2F2 + 7%2F4 We have to find a common denominator. How about 4?
What does a denominator of 4 do to the first fraction? WELL, for 5%2F2 you ask yourself: "How many times does 2 go into 4? The answer is 2.
SO you multiply 2 times 5 in the numerator and you get:
10%2F4

Now let's add --- both fractions have a common denominator:

10%2F4+%2B+7%2F4 = 17%2F4

Therefore, the TWO pieces added together add up to be 17%2F4. How much of the bread is left? Let's just subtract the 2 pieces (which was this fraction:17%2F4) from the whole 5 inch loaf.

5%2F1 - 17%2F4. Once again, how about if we make our common denominator 4? How many times does 1 go into 4? The answer is 4, so let's multiply 4 times 5 in the numerator and we get: 20%2F4


SO now that we have two common denominators, we can subtract:

20%2F4 - 17%2F4 = 3%2F4

Therefore, the third piece of the bread is 3%2F4 inch long.

I hope this helps. :-)