Volume flow rate through air ducts

[thatshowifeel]

Homework Statement

Air flows through two 8"x10" ducts that merge into a single 18"x14" duct. (Ducts are in 3D)
The average speed of air in each of the 8"x10" ducts is 30 ft/s.
What is the volume flow rate, of air in the 18"x14" section of the duct? Express the volume flow rate in ft^3/s
What is the average speed of air in the 18"x14" duct?

Homework Equations

The Attempt at a Solution

I really don't know where to start on this one

 

[SteamKing]

Given the dimensions of the ducts and the velocity of the flow thru them, how would you calculate the volumetric flow rate in each of the ducts? Read the problem carefully and look at the diagram.