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A cottage industry produces $x$ toys in a day, and the cost of producing each toy on that day is ₹$(55-x)$. If the total cost is ₹750, which quadratic equation represents the situation?
A$x^2+55x+750=0$
B$x^2-55x+750=0$
C$x^2-55x-750=0$
D$55x-x=750$
Answer & Solution
Correct answer: B. $x^2-55x+750=0$
Total cost = number of toys $\times$ cost per toy, so $x(55-x)=750$. This gives $55x-x^2=750$, or $-x^2+55x-750=0$. Multiplying by $-1$, we get $x^2-55x+750=0$.
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