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 in the following problems and find their solution by substitution method : Four kg of apples and 3 kg of guava together cost ? 36.50 while 3 kg of apples and 2 kg of guava cost ? 26.50. What is the price per kg of apples and guava ?

Form the pair of linear equations in the following problems and find their solution by substitution method : Anu has only 10 paise and 50 paise coins in her purse. If the total number of coinsis 17 and their total value is ? 4.50, find the number of each type of coins.

Form the pair of linear equations in the following problems and find their solution by substitution method : A’s present age is to B’s present age is 7 : 9. Twelve years ago, their ages were in the ratio 3:5. When would the ratio of their ages be 6 : 7 ?

Form the pair of linear equations in the following problems and find their solution by substitution method : If 1 is added to each of the two numbers, their ratio becomes 1 : 2 and when 5 is subtracted from each of these, the ratio becomes 5:11. Find the numbers.

Form the pair of linear equations in the following problems and find their solution by substitution method : Find the fraction which becomes to 2/3 when the numerator is increased by 2 and equal to 4/7 when the denominator is increased by 4 .

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 solutions graphically : 5 pencils and 7 pens together cost Rs 50 whereas 7 pencils and 5 pens together cost Rs 46. find the cost of one pencil and that of one pen.

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