其它
The average pocket money of the whole class is $91$ dollars. Each of the $24$ girls in the class has $92.5$ dollars on average. There are $18$ boys in the class, and their average pocket money is~\uline{~~~~~~~~~~}~dollars. 
Overseas Competition->Knowledge Point->Word Problem Modules->Average Problems 
More than average: $$(92.5-91)\times24=36$$.  Each boy should have $$36\div18=2$$ dollars less than the average, so each of them has $91-2=89$ dollars. 