Class 8 Maths Chapter 2 Question Answers - Linear Equations in One Variable

Q1: The breadth of a rectangular garden is 2/3 of its length. If its perimeter is 40 m, find its dimensions.
Ans: Let the length of the garden be x m its breadth
Perimeter = 2 [length + breadth]


Q2: Solve for x:

Ans:

=
(multiplying both sides by 15)

Hence x = 4 is the required number

Q3: The difference between two positive numbers is 40 and the ratio of these integers is 1 : 3. Find the integers.
Ans: Let one integer be x.
Other integer = x – 40
As per the conditions, we have

⇒ 3(x – 40) = x
⇒ 3x – 120 = x
⇒ 3x – x = 120
⇒ 2x = 120
⇒ x = 2
Hence the integers are 60 and 60 – 40 = 20.

Q4: The sum of a two-digit number and the number obtained by reversing its digits is 121. Find the number if it’s unit place digit is 5.
Ans: Unit place digit is given as 5
Let x be the tens place digit
Number formed = 5 + 10x
Number obtained by reversing the digits = 5 × 10 + x = 50 + x
As per the conditions, we have
5 + 10x + 50 + x = 121
⇒ 11x + 55 = 121
⇒ 11x = 121 – 55 (Transposing 55 to RHS)
⇒ 11x = 66
⇒ x = 6
Thus, the tens place digit = 6
Hence the required number = 5 + 6 × 10 = 5 + 60 = 65