Form the pair of linear equations in the following problems and find their solution by substitution method : Ten years ago, father was twelve times as old as his son and ten years hence he will be twice as old as his son will be. Find their present ages.

Form the pair of linear equations in the following problems and find their solution by substitution method : Five years ago, I was thrice as old as my son and ten years later I shall be twice as old as my son. How old are we now ?

Form the pair of linear equations in the following problems, and find their solutions (if they exist) by the elimination method : Five years ago, Nuri was thrice as old as Sonu. Ten years later, Nuri will be twice as old as Sonu. How old are Nuri and Sonu ?

Ram says to his son, 5 years ago, I was 7 times as old as you were and after 5 years I will be 3 times as old as you will be. Find their present ages.

form the pair of linear equations for the foIlowing problems and find their solution by substitution method: The larger of two supplementary angles exceeds the smaller by 18 degrees, Find them

Form the pair of linear equations in the following problems and find their solution by substitution method : A horse and 2 cows together cost ? 680. If a horse costs ? 80 more than a cow, find the cost of each.

Form the pair of linear equations for the foIlowing problems find their solution by substitution method: Five years hence, the age of Jacob will be three times that of his on. Five years ago, Jacob's age was seven times that of his son. What are their present ages?