On sunny days, Team A completed the total engineering quantity112, and on rainy days, it was112 * (1-40) =1/20.

On sunny days,115 of the total project completed by Team B, and on rainy days, it is115 * (1-20) = 4/75.

According to the meaning of the question, let the number of sunny days be x days and the number of rainy days be y days.

x * 1/ 12+y * 1/20 = 1

x * 1/ 12+y * 1/20 = x * 1/ 15+y * 4/75

Substitute X=3y for solving the second equation into the first equation, y= 10/3 days, and x= 10 days.