Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Differential Equations

Question:

At present, a firm is manufacturing 2000 items. It is estimated that the rate of change of production P with respect to additional number of workers x is given by $\frac{d P}{d x}=100-2 \sqrt{x}$. If the firm employs 25 more workers, then the new level of production of items is

Options:

2500

3000

3500

4500

Correct Answer:

3500

Explanation:

We have, $\frac{d P}{d x}=100-12 \sqrt{x}$

Integrating both sides with respect to x, we get

$P =\int(100-12 \sqrt{x}) d x$

$\Rightarrow P =100 x-8 x^{3 / 2}+C$            ....(i)

Initially x = 0, P = 2000

∴ 2000 = C

Putting C = 2000 in (i), we get

$P=100 x-8 x^{3 / 2}+2000$

When x = 25, we get

$P=2500-8(25)^{3 / 2}+2000=3500$

Hence, the new level of production is 3500 items.