The task is to generate the correct answer for a given math problem.

[Q]: Problem: meena wrote all the numbers from 1 to 29,999 inclusive . how many digits did she write in total ?
[A]: 138,889

[Q]: Problem: the average of runs of a cricket player of 10 innings was 33 . how many runs must he make in his next innings so as to increase his average of runs by 4 ?
[A]: 77

[Q]: Problem: two trains a and b starting from two points and travelling in opposite directions , reach their destinations 9 hours and 16 hours respectively after meeting each other . if the train a travels at 80 kmph , find the rate at which the train b runs .
[A]:
160