Q. If the 5 digit decimal number x679y is a multiple of 72. Find x and y.

• x679y is a multiple of 72,hence it must be divisible by 4,8.From this we will calculate y.
  for a number to be divisible by 4 the last two digit should be a multiple of 4,hence in place of y we can assume number 2,6.i.e 92 and 96.Now since the number is also divisible by 8 the last three digit must be divisible by 8,hence
  between 792 and 796 ,796 is eliminated(not divisible by 8).Hence y=2 is the correct assumption.Now,x6792 will also be divisible by 3 and 9.Hence we will sum up the digits.After checking the divisibility by 3 we get the probable values of y as 3,6,9.And on checking the divisibility by 9 we can see that 6 and 9 gets eliminated we get the number as 36792
• 10 years agoHelpfull: Yes(0) No(0)
• number must be divisible by 9 and 8.
  6+7+9=22
  next number divisible by 9 after 22 is 27
  it implies that sum of x and y must be 5
  now to be divisible by 8 last three digits must be divisible by 8 so y can be either 2 or 6
  x+y=5
  so y=2 and x=3
  hence the number id 36792
• 10 years agoHelpfull: Yes(0) No(0)