Question

A number consists of two digits the digit in the
sists of two digits the digit in the ten's place is twice the digit in the unit's
place. If 18 be subtracted from the number the digits
subtracted from the number the digits are reversed. Find the number​

Answer 1

Answer:

let the digit at tens place be x and units place be y

two digit no. 10x+y

reversed digits = 10y+x

a/c to 1condn

x=2y......(1)

A/C to2 given condn

10x+y-18=10y+x

10x-x+y-10y=18

9x-9y=18

9(x-y) =18

x-y=2.....(2)

2y-y=2

y=2

put y=2 in eqn (2)

x-2=2

x=4

therefore, two digit no. 10x+y

10*4+2

40+2

42