1.(25+25+10)/(1-1/3)=90
2.320*(1-1/8)-(320*1/8-5)=245
3.实际参加的人数是总人数的1/4
2/(1/4-1/5)*1/5=8
4.(36+12)/(1-2*12.5%)=64
5.15/(2/5-1/3)*2/5-15=75
6.(54*3-94)/(2-2/3)=66
7.(258*2/3+10)/(1-35%)-258=22
8.男生(98-3)/(1+1-1/10)=50女生98-50=48
9.甲班(93-3)/(9*2/10)=50乙班93-50=43
10.(50+10)/(3/4)+10=90
11.题不对
12.120*6/(1-2*1/4)=1440
13.(10.5/1.5/(7/3)）三次方=27 10.5/27=7/18
14.8*6*4/(1/3)/(4*5/4)=115.2
15.100/40%/5=50
16.中年级植的棵数是总数的1/8多5棵
(25+5)/(1-5/8-1/8)=120
17.(15-10)*24/15=8