Question

please please please answer my question with solutions both

Answer 1

(6)

Answer - Option : (4)

Explanation:

Let the numerator be x and the denominator is y.

The original fraction = x/y.

Given that the denominator of a rational number is greater than its numerator by 8.

y = x + 8.    -------------- (1)


Given that if the numerator is increased by 17 and denominator is decreased by 1, the number obtained is 3/2.

$\frac{x + 17}{y - 1} = \frac{3}{2}$

$\frac{x + 17}{x + 8 - 1} = \frac{3}{2}$

$\frac{x+17}{x+7} = \frac{3}{2}$

2(x + 17) = 3(x + 7)

2x + 34 = 3x + 21

2x = 3x + 21 - 34

2x = 3x - 13

2x - 3x = -13

-x = -13

x = 13.


Substitute x in (1), we get

y = x + 8

y = 8 + 13

y = 21.



Therefore the original fraction = 13/21.



(7)

Answer - Option: (3)


Explanation: 

Given Selling price of a book = 100.

Given Gain = 20%.

We know that Cost price = Selling price - Profit

                                           = 100 - 20

                                           = 80.



Now,

We know that Gain% = (Gain/Cost price) * 100

                                    = (20/80) * 100

                                    = (1/4) * 100

                                    = 25.


Therefore the Gain percent = 25%.



Hope this helps!