X*L 1=27*L2

8*L 1=(30-X)*L2

X= 18 when comparing the two formulas.

Assume that the total project amount is 1 A, and it will be completed every month1/3 b. Cooperation takes x months.

( 1/3+ 1/6)* x = 1x = 2

Don't worry about the cost! Try it yourself. The answer upstairs is correct.

Let a month x a month y1/3 * x+1/6 * y =1,so that y=6-2x and 12*x+5y are the minimum values.

Do the math yourself! All right!