The number has 6 digits.
the value of the smallest digit is 0.01
the value of the largest digit is 8000
the digit in the tens place is 2 less than the digit in the hundreds place.
the sum of the digit in the tens place and the digit in the hundreds place is equal to the digit in the thousands place
the digit in the tenths place has the same value in every place.
the remaining digit is the largest even digit.
what is the mystery number?

It has 6 digits, and smallest number and biggest number is given.
Smallest digit= 0.01 or the tenths =1
Largest digit is 8000 = thousands
tens value = hundreds – 2 = X
hundreds = tens + Hundreds = 8 (thousands value)
ones = largest even digit = 8
tenths= the same value with every place
hundredths = 1

Thus,
Thousands = 8
hundreds = 3 + 5 = 8 hundreds = 5
tens = 5 – 2  = 3
ones = 8
.
tenths = 3
Hundredths = 1

Therefore the mystery number is 8538.31