Mathematics
If -5 is a root of the quadratic equation 2x^2 + px - 15 = 0 and the quadratic equation p(x2 + x) + k = 0 has equal roots, then the value of k is: 1. 7/4 2. 5/4 3. 3/4 4. 1/4
Related Questions
The value of the discriminant of the equation, 3x2 = - 11x - 10, is:
1
0
4
9
Case Study II
Raman Lal runs a stationery shop in Pune. The analysis of his sales, expenditures and profits showed that for x number of notebooks sold, the weekly profit (in ₹) was P(x) = - 2x2 + 88x - 680. Raman Lal found that:
- He has a loss if he does not sell any notebook in a week.
- There is no profit no loss for a certain value x0 of x.
- The profit goes on increasing with an increase in x i.e. the number of notebooks sold. But he gets a maximum profit at a sale of 22 notebooks in a week.
Now answer the following questions :
1. What will be Raman Lal’s profit if he sold 20 notebooks in a week?
- ₹ 144
- ₹ 280
- ₹ 340
- ₹ 560
2. What is the maximum profit that Raman Lal can earn in a week?
- ₹ 144
- ₹ 288
- ₹ 340
- ₹ 680
3. What is Raman Lal’s loss if he does not sell any notebooks in a particular week?
- ₹ 0
- ₹ 340
- ₹ 680
- ₹ 960
4. Write a quadratic equation for the condition when Raman Lal does not have any profit or loss during a week.
- 2x2 - 44x + 340 = 0
- x2 + 44x - 340 = 0
- x2 - 88x + 340 = 0
- x2 - 44x + 340 = 0
5. What is the minimum number of notebooks x0 that Raman Lal should sell in a week so that he does not incur any loss?
- 0
- 10
- 11
- 12