NCERT Class 8 Mathematics Solutions: Chapter 2 – Linear Equations in One Variable Exercise 2.4 Part 1 (For CBSE, ICSE, IAS, NET, NRA 2022)

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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