Question #22669

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Answer 1 · 2017-12-15T15:54:54

Here are two ways to solve this.

Method 1

Set up a proportion. For example, using grams of fiber to cups of oats, we could write:

$4 : \frac{1}{2} = f : 3 \frac{1}{2}$ $4:1/2 = f:3 1/2$ Or, using fractions: $\frac{4}{\frac{1}{2}} = \frac{f}{3 \frac{1}{2}}$ $4/(1/2) = f/(3 1/2)$

Use the improper fraction $\frac{7}{2}$ $7/2$ instead of the mixed number $3 \frac{1}{2}$ $3 1/2$ .

$\frac{4}{\frac{1}{2}} = \frac{f}{\frac{7}{2}}$ $4/(1/2) = f/(7/2)$ .

Now solve the proportion:

$4 \cdot \frac{7}{2} = \frac{1}{2} \cdot f$ $4 * 7/2 = 1/2 * f$

$14 = \frac{1}{2} f$ $14 = 1/2 f$

$f = 28$ $f = 28$

$28$ $28$ grams of fiber.

Method 2

Notice that there are $7$ $7$ half-cups in $3 \frac{1}{2}$ $3 1/2$ cups.

Each half-cup of oats contains $4$ $4$ grams of fiber, so $7$ $7$ half-cups contain #7 * 4 = 28$ grams of fiber.

Answer 2 · 2017-12-15T16:00:50

28 grams of fiber.

Its given that 1/2 cup of oats has 4 grams fiber
So, 1 cup of oats will have = $\frac{4}{\frac{1}{2}}$ $4/(1/2)$ = 8 grams of fiber,

Now, how much fiber in $3 (\frac{1}{2})$ $3(1/2)$ cups = ?

For the ease of calculate, convert $3 (\frac{1}{2})$ $3(1/2)$ to improper fraction and it would become $\frac{7}{2}$ $7/2$

Now, we know that 1 cup oats has = 8 grams fiber
Therefore, $\frac{7}{2}$ $7/2$ cups of oats will have = $8 \times \frac{7}{2}$ $8xx7/2$ = 28 grams