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

A. $x + y = 5, 2x + 2y = 10$

B. $2x + y - 6 = 0, 4x - 2y - 4 = 0$

C. $x - y = 8, 3x - 3y = 16$

D. $x - 2y = 0, 3x + 4y - 20 = 0$

Choose the correct answer from the options given below:

The value of k, for which the system of equations 3x-ky-20 = 0, and 6x-10y+40 = 0 has no solution, is:

When thrice of x is added to 7, we get 13, then the value of x is :

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:

Read the information given below carefully and answer the question that follows:

Question: How much does Ajay pay to his driver every month as Salary?

Statements:

i. Rakesh pays 20% more per month, to his driver than Ajay as Rakesh's driver has a 15 year experience. Moreover, Ajay pays 30% more per month than Karan as Karan's driver has mere 5 years of experience.

ii. As Karan would avail 10% discount on drivers's salary by paying for 6 months in advance, Karan paid his driver Rs 54000 for 6 months in advance.

Determine which of the following is True in order to solve the asked question?

The total age of P and Q is 18 years more than the total age of Q and R. R is how many years younger than P ?

Reena is twice as old as Sunita. Three years ago, Reena was three times as old as Sunita. What is present age of Reena?