Question
For which values of x is the expression 25x - 5x² - 100
positive?Solution
ATQ,
So, 25x - 5x² - 100 > 0
Or, 5x² - 25x + 100 < 0
Or, 5x² - 20x - 5x + 100 < 0
Or, 5x(x - 4) -5(x - 4) < 0
Or, (5x - 5)(x - 4) < 0
So, x = 1 and x = 4
Hence, the expression is positive between 1 and 4.
Mohini went shopping to buy a shirt with some money. She selected a shirt, which is marked Rs.200 higher price than the money she had. But shopkeeper g...
A shopkeeper mixes 40 kg sugar worth Rs.15 per kg with 160 kg sugar worth Rs. 25 per kg. At what rate should he sell the mixture per kg to gain a profit...
A and B invest in a business in the ratio 4 : 5. After 10 months B leaves the business after withdrawing his investment. In the first year the business...
After selling 20 pens, a Shopkeeper earn a profit of the selling price of 6 books. While selling 20 books, a shopkeeper losses a selling price of 8 pen...
A fruit seller buys oranges at the rate of 11 for ₹55. How many oranges should he sell for ₹54 to gain 20%?
Shyam marked an article 25% above cost price and sold it for Rs. 1080 after allowing a discount of 10%. Find his profit (in Rs.).
An article is sold at 15 (1/2) % profit. If its C.P. is increased by Rs. 40 and at the same time if its SP is also increased by Rs. 30, then % of profit...
The cost price of an article is Rs. (4n + 90). It is marked 25% above its cost price and sold after allowing a discount of Rs. 150. If the selling price...
Kavita purchased a microwave oven for Rs. 24,200 and managed to sell it for Rs. 27,830. Determine her percentage profit.
A trader marks an article 50% above its cost price. He sells it at a discount of 20% on the marked price. If instead he had given a discount of only 10%...
Relevant for Exams:
