To multiply fractions, multiply the numerators together and then multiply the denominators together:

\( \frac{3}{9} \) x \( \frac{1}{5} \) = \( \frac{3 x 1}{9 x 5} \) = \( \frac{3}{45} \) = \(\frac{1}{15}\)

To find the average of these 4 numbers add them together then divide by 4:

\( \frac{11 + 5 + 9 + 7}{4} \) = \( \frac{32}{4} \) = 8

If a single cook can bake 2 large cakes per hour and the kitchen is available for 4 hours, a single cook can bake 2 x 4 = 8 large cakes during that time. 36 large cakes are needed for the party so \( \frac{36}{8} \) = 4\(\frac{1}{2}\) cooks are needed to bake the required number of large cakes.

If a single cook can bake 16 small cakes per hour and the kitchen is available for 4 hours, a single cook can bake 16 x 4 = 64 small cakes during that time. 100 small cakes are needed for the party so \( \frac{100}{64} \) = 1\(\frac{9}{16}\) cooks are needed to bake the required number of small cakes.

Because you can't employ a fractional cook, round the number of cooks needed for each type of cake up to the next whole number resulting in 5 + 2 = 7 cooks.

To add these radicals together their radicands must be the same:

3\( \sqrt{28} \) + 4\( \sqrt{7} \)
3\( \sqrt{4 \times 7} \) + 4\( \sqrt{7} \)
3\( \sqrt{2^2 \times 7} \) + 4\( \sqrt{7} \)
(3)(2)\( \sqrt{7} \) + 4\( \sqrt{7} \)
6\( \sqrt{7} \) + 4\( \sqrt{7} \)

Now that the radicands are identical, you can add them together:

To take the square root of a fraction, break the fraction into two separate roots then calculate the square root of the numerator and denominator separately:

\( \sqrt{\frac{64}{16}} \)
\( \frac{\sqrt{64}}{\sqrt{16}} \)
\( \frac{\sqrt{8^2}}{\sqrt{4^2}} \)
\( \frac{8}{4} \)
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