The sum of the digits of a two digit number is 7. If the digits are reversed, the new number is equal to 3 less than four times the original number. What is the original number?

let digit in unit's place be x and that in ten's place of the original number be y

original number = 10y + x

given

x + y = 7 ----------(i) (sum of digits)

after the digits are reversed, the new number is 10x + y

given that new number = 4*(original number ) -3

therefore ( 10 x +y) = 4*(10y + x ) - 3

or 10x + y = 40y + 4x - 3

or 6x -39 y = -3 ----------(ii)

system is

x + y = 7 ----------(i)

6x - 39 y = -3 ----------(ii)

solving

eliminating x

6x + 6y = 42----------(i)

6x - 39 y = -3 ----------(ii)

subtracting

45 y = 45 or y =1

substituting x + 1 = 7 or x = 6

therefore

x = 6 , y = 1

original number = 16

other word problems with some explanation

------------------------------------------------------------

disclaimer:

There is no guarantee about the data/information on this site. You use the data/information at your own risk. You use the advertisements displayed on this page at your own risk.We are not responsible for the content of external internet sites. Some of the links may not work

## No comments:

## Post a Comment

please leave your comments