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3 years ago

If 12 pencils cost $4.00, how much does 20 pencils cost?

Mathematics

2 answers:

Sedaia [141]3 years ago

6 0

Answer:

$\huge\boxed{\$6\dfrac{2}{3}\approx\$6.67}$

Step-by-step explanation:

$\bold{METHOD\ 1:}\\\\\begin{array}{ccc}12&-&\$4.00\\\\20&-&\$x\end{array}\qquad\text{cross multiply}\\\\12x=(20)(4)\\\\12x=80\qquad\text{divide both sides by 12}\\\\x=\dfrac{80}{12}\\\\x=\dfrac{20}{3}\\\\x=6\dfrac{2}{3}\Rightarrow x\approx6.67$

$\bold{METHOD\ 2:}\\\\12\ \text{pencils cost}\ \$4.00.\\\\1\ \text{pencil cost}\ \$4.00:12=\$\dfrac{4}{12}=\$\dfrac{1}{3}\\\\20\ \text{pencils cost}\ \$\dfrac{1}{3}\times20=\$\dfrac{20}{3}=\$6\dfrac{2}{3}\approx\$6.67$

natita [175]3 years ago

4 0

Answer:

$6.66

Step-by-step explanation:

20 times 4 = 80 and 80 divided by 12 is 6.66666667

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Answer details

Grade: Middle school

Subject: Mathematics

Chapter: Mixtures and ratios

Keywords: mixture, paint, red paint, blue paint, Mrs. Cleaver, purple paint, fraction, each container, five containers, divides, times, equally divide, mixes, liters.

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