# NCERT Class 8 Mathematics Solutions: Chapter 2 –Linear Equations in One Variable Exercise 2.4 Part 1

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**Question: 1** Amina thinks of a number and subtracts from it. She multiples the result by 8. The result now obtained is 3 times the same number she thought of. What is the number?

**Answer:**

Let Amina think a Number.

According to the question,

Hence, the number is 4.

**Question: 2** A positive numbers is 5 times another number. If 21 is added to both the numbers, then one of the new numbers becomes twice the other new number. What are the numbers?

**Answer:**

Let positive number

Another number will be

Another number

**Question: 3** Sum of the digits of a two-digit number is 9. When we interchange the digits, it is found that the resulting new number is greater than the original number by 27. What is the two-digit number?

**Answer:**

Let the digit at tens place be x then digit at one place will be

Original number =

After interchanging the digits, the new number

Original number

Thus, the number is .

**Question: 4** One of the two digits of a two-digit number is three times the other digit. If you interchange the digits of this two-digit number and add the resulting number to the original number, you get 88. What is the original number?

**Answer:**

Let the digit at tens place be.

Then digit at ones place will be.

Original two digit number =

After interchanging the digits, the new number =

According to the question,

Original number + New number = 88

Hence, Original number