The sum of digits of a two digit number is 7. when the digits are reversed, the number is decreased by 9. find the number. please show the working
KVaishu:
Is the answer 54
Oh.. sorry.. it is 43
Answers
Answered by
39
Hope this helps you
Attachments:
Answered by
44
Let the unit digit = x
and let the tens digit = y
Then the no. is = 10y+x
Reversed No = 10x+y
Case 1. x+y = 7.............(1)
Case 2.
= 10x+y = 10y+x-9
= 9x-9y = 9
= x-y = 1.............(2)
= adding (1) and (2)
= 2x = 8
= x = 4
put the value of x in (1)
= 4+y = 7
= y = 3
then the Number is 10y+x
= 10 . 3+4
= 34. is the No.
and let the tens digit = y
Then the no. is = 10y+x
Reversed No = 10x+y
Case 1. x+y = 7.............(1)
Case 2.
= 10x+y = 10y+x-9
= 9x-9y = 9
= x-y = 1.............(2)
= adding (1) and (2)
= 2x = 8
= x = 4
put the value of x in (1)
= 4+y = 7
= y = 3
then the Number is 10y+x
= 10 . 3+4
= 34. is the No.
The higher number should be the answer
Please check
no. is either 43 and 34 both are correct.
The question says that if the number's digits are reversed, the number is decreased by 9. So, the original number is the higher number.
This is not to argue with you
Anyway you can edit your answer
: D
o. K.
both of you, thank you for your help
Similar questions