Question 1205896
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Hi
Mrs Lee went shopping with a certain amount of money. If she wanted to buy 15 shirts she would need another $150. If she bought 5 shirts she would have $250 left.  How much did a shirt cost.

Let cost of a shirt be S
Since purchasing 15 shirts would've required an additional $150, amount she had, was 15S - 150
And, since purchasing 5 shirts would've left her with $250, amount she had, was 5S + 250
We now set the 2 expressions equal to each other, as follows:  15S - 150 = 5S + 250
                                                                15S - 5S = 250 + 150
                                                                     10S = 400
                                                  Cost of a shirt, or {{{highlight_green(matrix(1,5, S, "=", 400/10, "=", highlight("$40")))}}}</pre>