Question

the sum of the digit of a two-digit number is 10. if 36 is subtracted from the number ,the digit inchange their places.find the place

Answer 1

let the tens place digit be x and ones olace digit be y

a.t.q.
x+y=10...........(i)
and.. 10x+y-36=10y+x
=> 10x-x+y-10y=36
=>9x-9y=36
=>x-y=4......(dividing both side by 9)..(ii)

adding equation (i) and (ii) we get
x+y=10
x-y=4
____________
2x=14
x=7...
substituting the value of x in equation (i)
x+y=10
7+y=10
y=10-7
y=3
so...the number is 73..