The digits of a two digit no differ by 7. If the digits are interchanged and the resulting no is added to the original no we get 121. Find the original no.
Answers
Hi please mark this answer the brainliest.
let the number be xy
tens place = 10x
ones place = y
The digits of a two digit number differ by 7
x - y = 7.....[1]
if the digits are interchanged and the resulting number is added to the original number we get 121
so,
10y + x + 10x +y = 121
11x +11y = 121
now,
x + y = 11.....[2]
now , [1] and [2] since
x - y = 7
x +y = 11
on adding them
2x = 18
x = 9
now y = x - 7
= 9 -7
=2
hence the original number is xy
= 92
hope it helps u
:)
Step-by-step explanation:
Let the unit digit be x
and ten's digit be 7-x
Number = 10(7-x)+ x
= 70-9x
Inter changed number = 10x+7-x
= 9x+7
According to question,
= 70-x+9x+7 =121
= 8x+77=121
= 8x= 121-77
= x= 44/8