The weight of salt in the first cup of brine is: a \u( a+ 1).

The weight of salt in the second cup of brine is: b \u( b+ 1).

Solution:

[a \(a+ 1)+b \(b+ 1)]\2

Simplification: [(AB+1/2A+1/2B) ÷ (A+B+AB+1)]:1

2. Assume that the speed of A is 13 and the speed of B is 1 1.

Then the total distance is (13+11) ÷ 0.5 = 48.

Then the time for A to catch up with B is 48 ÷ (13-11) = 24 (hours).