Urgent! Math problem: It takes 12 days for an underground pipeline A to be laid alone, and 18 days for B to be laid alone. How many days will it take if A and B are paved from both ends? To solve this
Urgent! Math problem: It takes 12 days for an underground pipeline A to be laid alone, and 18 days for B to be laid alone. How many days will it take if A and B are paved from both ends? To solve this equation
Solution: Suppose it takes X days for Party A and Party B to pave from both ends, and the total length of the road section is 1.
[( 1/ 12)+( 1/ 18)]x = 1
x = 1/[( 1/ 12)+( 1/ 18)]
= 1/30/( 12* 18)
=7.2
A: It takes 7.2 days.