It has been observed that the number of instructions executed between page faults is directly proportional to the number of page frames allocated to a program. If the available memory is doubled, the mean interval between page faults is also doubled. Suppose that a normal instruction takes $1\: microsec,$ but if a page fault occurs, it takes $2001\: \mu sec (i.e., 2\: msec)$ to handle the fault. If a program takes $60\: sec$ to run, during which time it gets $15,000$ page faults, how long would it take to run if twice as much memory were available?