Question 959333
The problem uses the following formula
Flow rate = 26.9 x d^2 x sqrt P
we have two hoses with d = 3 each and P and 4p for pressure, therefore we have the following formula
(26.9 * 3^2 * sqrt(P)) + (26.9 * 3^2 * sqrt(4P)) = 2430
(242.1*sqrt(P)) + (242.1 * sqrt(4P)) = 2430
Note that sqrt(4P) = 2*sqrt(P) 
(242.1 * sqrt(P)) + (484.2 * sqrt(P)) = 2430
726.3 * sqrt(P) = 2430
sqrt(P) = 3.345724907
square both sides of =
P = 11.193875154 approx 11.2
The two pressure values are 11.2 psi and 44.8 psi