CBSE Class 10-Mathematics: Chapter –4 Quadratic Equations Part 25
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Question 11:
A factory kept increasing its output by the same percent ago every year. Find the percentage if it is known that the output is doubled in the last two years.
Answer:
According to question,
Question 12:
Two pipes running together can fill a cistern in minutes. if one pipe takes minutes more than the other to fill it, find the time in which each pipe would fill the cistern.
Answer:
Let the faster pipe takes minutes to fill the cistern and the slower pipe will take minutes.
According to question,
Question 13:
If the roots of the equation are equal, prove that
Answer:
For equal root s,
Question 14:
Two circles touch internally. The sum of their areas is and the distance between their centers is . Find the radii of the circles.
Answer:
Let be the radius of two circles
According to question,

Two Circles Touch Internally
Put the value of in eq. …(i)
When