A student finds the average of 10 positive integers. Each integer contains two digits. By mistake, the boy interchanges the digits of one number say ba for ab. Due to this, the average becomes 3.6 less than the previous one. What was the difference of the two digits a and b?

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is C 4
Let the two numbers be ab and ba
ab=(10a+b) and ba=10b+a
If the change in average of 10 numbers is 3.6, then the change in sum is 36.
$a b - b a = 10 (a - b) + (b - a) = 10 (a - b) - (a - b) = 9 (a - b) = 36$
Therefore, the difference between numbers $= (a - b) = \frac{36}{9} = 4$

Suggest Corrections

Similar questions

Q. Mr. Manmohan calculated the average of 10 'three digit numbers'. But due to mistake, he reversed the digits of a number and thus his average increased by 19.8. The difference between the unit digit and hundreds digit of that number is :

Q. The difference between a two digit given number

(a b)

and the number obtained by interchanging the digits

(b a)

27

. Then find

a - b

Q. The average of the two digit numbers, which remain the same when the digits interchange their positions is:

Q. If a two-digit positive integer has its digits reversed,the resulting integer differs from the original by 27. By how much do the two digits differ?

The difference between a two – digit number and the number obtained by interchanging the positions of its digits is 36. What is the difference between the two digits of that number?

Join BYJU'S Learning Program

A student finds the average of 10 positive integers. Each integer contains two digits. By mistake, the boy interchanges the digits of one number say ba for ab. Due to this, the average becomes 3.6 less than the previous one. What was the difference of the two digits a and b?

The correct option is C 4Let the two numbers be ab and ba ab=(10a+b) and ba=10b+a If the change in average of 10 numbers is 3.6, then the change in sum is 36. ab−ba=10(a−b)+(b−a)=10(a−b)−(a−b)=9(a−b)=36 Therefore, the difference between numbers =(a−b)=369=4