Mathematical engineering a and b

[train of thought analysis]

This problem is to solve simple production problems with mathematical knowledge, which is also the teaching purpose of junior high school mathematics.

The first problem is engineering. There are three quantities in engineering problems: total workload, work efficiency and working time. The relationship between these three quantities is:

Total amount of work = working efficiency × working time.

The second question only needs to find out how much money each team of A, B and C should take every day. The first question can find out what each team of A, B and C can do alone.

For the required number of days, we can find out which team spends the least money to complete the project alone within the specified time.

[Problem solving process]

(1) Group A is set to be completed in X days, Group B in Y days and Group C in Z days.

So judging from the meaning of the question,

1/x+ 1/y = 1/6( 1)

1/y+ 1/z = 1/ 10(2)

1/x+ 1/z =(2/3)*( 1/5)(3)

In order to solve this system of equations,

x= 10，y= 15，z=30

So team A 10 days, team B 15 days and team C 30 days.

(2) Assume the daily salary of Team A, Team B and Team C..

So judging from the meaning of the question,