Answer:
See explanation
Step-by-step explanation:
If the mystery number rounds to 700, then it has 3 digits before decimal points and two digits after decimal point.
Hence, the mystery number is
[tex]a b c . d e[/tex]
The digit in the tenth place is double the digit in the tens place, so
[tex]d=2b[/tex]
If b = 1, then d = 2
If b = 2, then d = 4
If b = 3, then d = 6
If b = 4, then d = 8
The difference between the digit in the hundreds place and the ones place is 3, so
[tex]a-c=3[/tex]
The first digit can be only 7, because b < 5 and the number rounds to 700. So
If a = 7, then c = 4
All possible answers:
714.2e
724.4e
734.6e
744.8e,
where e is an arbitrary digit from 0 to 9.
There are 40 possible numbers which match the situation.
