Express the following statements in the form of simultaneous linear equations :
The total value of 3 copies (khata) and 2 pens is Rs. 44 and that of 4 copies (khata) and 3 pens is Rs. 61.

(xvii) Express the following statements in the form of simultaneous linear equations : (a) If 2 is added to both the numerator and denominator of a fraction it becomes (5)/(7) and If 1 is substracted from both the numerator and denominator the value of the fraction becomes (1)/(2) .

Express the following statements in the form of simultaneous linear equations : The sum of two different numbers is 80 and 3 times of the difference of the two numbers is 20 more than the greater one.

Express the following statements in the form of simultaneous linear equations and solve them by drawing graphs : (ii) At present the age of a father is 28 years more than that of his son. After 10 years the age of father will be 3 times of the age of his son. Find the present ages of both father and son.

Express the following statements in the form of simultaneous linear equations : If 2 is added to both the numerator and denominator of a fraction, its value becomes 7/9 and if 3 subtracted from both the numerator and denominator of it, the fraction becomes 1/2 .

Express the following statements in the form of simultaneous linear equations : (iv) The tens' digit of a number of two digits is double of its unit's digit. The number, obtained by reversing the two digits of the number, is 27 less than the original number.

Express the following statements in the form of simultaneous linear equations and solve them by drawing graphs : (i) The sum of two numbers is 12 and their difference is 4. Find the numbers.

Express the following statements in the form of a linear equations of two variables and draw the graph of them : (i) The sum of two numbers is 15.

Express the following statements in the form of simultaneous linear equations and solve them by drawing graphs : (iv) A boat travels 56 km in 4 hours in favour of the current and 48 km in 8 hours against the current. Find the velocity of the boat in steady water and the velocity of the current.

Express the following statements in the form of two simultaneous linear equations in two variables and determine whether these equations are solvable or not by the method of finding the relations among the ratios of the co-efficients of the same variables and the constant terms : Debsmita bought 3 pens and 4 pencils for Rs. 42. Her friend Nayana also bought 9 pens and a dozen of pencils for Rs. 126.