Question

the digit at tens place of two digit number is 2 times the digit and famous place in digits are reversed did number becomes 18 less than the original number what is the original number

Answer 1

suppose unit digit of number is 'x'
then tens digit will be '2x'
the number will be 10(2x) + x
then reversed number will be 10(x) + 2x

equation

10(2x) + x -18 = 10(x) + 2x
21x - 18 = 12x
21x - 12x = 18
9x = 18
x = 2
so,unit digit of number = 2
tens digit of number = 2×2=4
number = 42.