= 120÷2/5

=300

2、8+ 12+2 1=4 1

Total number of people in workshops I, II and III: 260 ÷ (21/41-8/41) = 820.

The number of people in the second workshop is 820× 12/4 1=240.

3、 1÷( 1/ 10+ 1/ 15)=6

4、2/3÷( 1/2- 1/3)=4

5,1÷ [(1/6+112+1/0) ÷ 2] = 40/7 = 5 and 5/7.