The product of two positive numbers is 189 and their quotient is $\frac{3}{7}$. Find the sum of these numbers.

In an examination which had 200 questions, students score 4 marks for every correct answer and lose 1 mark for every wrong answer.

A student attempted all the 200 questions and scored 200 marks. The number of questions, student answered correctly in the examination, is:

The present age of a father is 4 years more than double the age of his son. After 10 years, the father's age is 30 years more than his son. Then the present age of father is:

Which of the following pairs of linear equations is/are consistent?

A. x + y – 5 = 0, 3x + 2y – 10 = 0

B. 3x – 2y – 6 = 0, 6x – 4y – 12 = 0

C. x – y – 9 = 0, 3x – 3y – 27 = 0

D. x + y – 4 = 0 , 3x + 3y – 12 = 0

Choose the correct option from the given below:

Which one of the following pair of linear equations is/are inconsistent?

A. x − y = 6, x − y = 13

B. 2x − 10y = 15, 7x − 35y =25

C. x − y = 15, 5x - 5y = 75

D. 7x − 9y − 3 = 0, 14x − 18y − 8 = 0

Choose the correct answer from the options given below:

Which of the following pair of linear equations is / are inconsistent?

(A) $x - y = 5$; $3x - 3y = 10$

(B) $2x + 3y = 4$; $4x + 6y = 8$

(C) $9x + 6y = 6$; $3x + 2y = 3$

(D) $2x + 5y = 2$; $6x - 15y = 4$

Choose the correct answer from the options given below:

If $2^{(x+y)} = 64$ and $128^{(x-y)} = 2$, then what is the value of x?