Q28 of 186 Page 3

Champa went to a 'sale' to purchase some pants and skirts. When her friends asked her how many of each she had bought, she answered, "The number of skirts is two less than twice the number of pants purchased. Also the number of skirts is four less than tbur times the number of pants purchased". Find how many pants and skirts Champa bought?

Let the number of pants = x

and the number of skirts = y


According to the question


Number of skirts = 2(Number of pants) – 2


y = 2x – 2 …(i)


Also, Number of skirts = 4(Number of pants) – 4


y = 4x – 4 …(ii)


Substituting the value of y = 4x – 4 in eqn (i),we get


4x – 4 = 2x – 2


⇒ 4x – 2x – 4 + 2 = 0


⇒ 2x = 2


⇒ x = 1


Now, substitute the value of x in eqn (ii), we get


y = 4(1) – 4 = 0


∴ x = 1, y = 0 is the solution of the pair of linear equations.


We can solve this problem through graphically also



Hence, the number of pants she purchased is 1 and the number of skirts, she purchased is zero i.e., she didn’t buy any skirt.


More from this chapter

All 186 →
26

10 students of class X took part in mathematics quiz. If the number of girls is 4 more than the number of boys, find the number of boys and girls who took part in the quiz.

 27

Form the pair of linear equations in the following problems and find their solutions graphically. Two years ago, a father was five times as old as his son. Two years later, his age will be 8 more than three times the age of the son.

 29

Priyanka purchased 2 pencils and 3 erasers for Rs. 9. Sayeeda purchased 1 pencil and two erasers for Rs. 5. Find the cost of one pencil and one eraser.

 1

Solve the following pair of linear equations by substitution method:

7x— 15y = 2


x + 2y = 3