When we perform a 'Digit-Slide' on a number then we move its unit's digit to front of the number for example the result of 'Digit Slide' on 6471 is 1647. Let 'z' be the smallest positive integer with 5 as its unit's digit such that the result of digit slide on the number equals 4 times the number. How many digits will 'z' have?
(a)7
(b)7
(c)4
(d)3

• unit digit is 5 so lets have 3digit no xx5.
  bt if we multiply it by 4 we get 0 in unit place so 10's digit should be 0. so we have x05
  nw if we multiply it by 4 then x20.so third digit will be 2 and digit should be xxx=205, but if we multiply it by 4 we get 205*4 = 820, but by sliding we get only 520,so 4th digit should be 8, now no is 8205, and 8205*4= 32820, so 5th digit should be 2 and no will be 28205 now multiply by 4 and you will get no should as 128205...hence of 6 digit
• 10 years agoHelpfull: Yes(17) No(0)
• the smallest positive integer is,z=128205
  digit slide,512820=4(128205)
  so,z has 6 digits
• 10 years agoHelpfull: Yes(7) No(7)
• ans is 6.......
  there r two 7 in option (wrong)
  on will be six
  
• 10 years agoHelpfull: Yes(0) No(0)
• will eat is the correct answer.
  
• 10 years agoHelpfull: Yes(0) No(1)
• Letting X be the positive integer in question, 4X is the result of the digit slide on X.
  The units digit of X is 5, and 5• 4 = 20, so the units digit of 4X is 0, and the last two digits
  of X are 05.
  We can continue the argument as follows:
  05 • 4 = 20, so the last two digits of 4X are 20, and the last three digits of X are 205,
  205 • 4 = 820, so the last three digits of 4X are 820, and the last four digits of X are
  8205,
  8205 • 4 = 32820, so the last four digits of 4X are 2820, and the last five digits of X are
  28205,
  28205 • 4 = 112820, so the last five digits of 4X are 12820, and the last six digits of X are
  128205, and finally
  128205 • 4 = 512820, which just happens to be the result of a digit slide on 128205.
  Hence, 128205 is the smallest positive integer with 5 as its units digit such that the result
  of a digit slide on the number equals 4 times the number.
• 8 years agoHelpfull: Yes(0) No(0)