A car is travelling at a uniform speed.
The driver sees a milestone showing a 2digit number. After travelling for an hour the driver sees another milestone with the same digits in reverse order.
After another hour the driver sees another milestone containing the same two digits as in the first one but the two digits separated by a zero(0).
What is the speed of the car?
(In reply to
re: please ignore by fwaff)
There being an analytic solution already, I wasn't going to post the brute force program, but it looks like fwaff expects one so I shan't disappoint:
FOR a = 12 TO 89
a$ = LTRIM$(STR$(a))
b$ = RIGHT$(a$, 1) + LEFT$(a$, 1)
b = VAL(b$)
c = 2 * b  a
c$ = LTRIM$(STR$(c))
IF LEFT$(c$, 1) = LEFT$(a$, 1) AND RIGHT$(c$, 1) = RIGHT$(a$, 1) AND MID$(c$, 2, 1) = "0" THEN
PRINT a, b, c
END IF
NEXT
The only preanalysis that went in is that the threedigit milestone came after the twodigit ones, so the miles were going up rather than down, giving the limits for the first milestone as 12 to 89.

Posted by Charlie
on 20031003 11:21:10 