Working together 1 hour, we have already completed1/7.5+1/5 =1/3, and the remaining 2/3 are completed by junior two students. We still need (2/3)/(1/5).
So * * * takes 13/3 hours.
9. Let X people do it for 2 hours, and the equation can be listed according to the meaning of the question.
(x/80)*2+(x+5)/80*8=3/4
X=2 to solve this equation.
So the two men began to sort out the information.
Teaching plan of mathematical natural measurement 1
Activity content:
Learning natural measurement
Activity objectives:
<