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Ali went to a store that sells T-shirts. It’s offering $ 180 for 6 T-shirts or $270 for 9 T-shirts.

Find the constant of proportionality.
Write the equation of proportionality.
What will be the price of 15 T- shirts.
If the price of a T-shirt changed to $43. What will be the price of 7 T- shirts.

1 Answer

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Explanation:

To find the constant of proportionality, we can set up a ratio between the number of T-shirts and their respective prices.

Let's denote the number of T-shirts as 'n' and the price as 'p'.

Given that the store offers $180 for 6 T-shirts and $270 for 9 T-shirts, we can set up the following ratios:

180/6 = p/n

270/9 = p/n

We can simplify these ratios by dividing both the numerator and denominator by their greatest common divisor (GCD). The GCD of 180 and 6 is 6, and the GCD of 270 and 9 is also 9. Simplifying the ratios, we get:

30 = p/n

30 = p/n

Since the ratios are equal, we can write the equation of proportionality as:

p/n = 30

The constant of proportionality is 30.

To find the price of 15 T-shirts, we can use the equation of proportionality:

p/n = 30

Substituting the values, we get:

p/15 = 30

Solving for 'p', we find:

p = 30 * 15 = 450

Therefore, the price of 15 T-shirts will be $450.

If the price of a T-shirt changed to $43, we can use the equation of proportionality to find the price of 7 T-shirts:

p/n = 30

Substituting the values, we get:

43/n = 30

Solving for 'n', we find:

n = 43 / 30 * 7 = 10.77 (rounded to two decimal places)

Therefore, the price of 7 T-shirts, when each T-shirt costs $43, will be approximately $10.77.

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