The following diagram shows a $4-$step process that begins with Operation $1$ and ends with Operation $4.$ The rates shown in each box represent the effective capacity of that operation.

a$.$ Determine the capacity of this process.

Capacity

per hour

b$.$ Which action would yield the greatest increase in process capacity: $(1)$ increase the capacity of Operation $1$ by $15$ percent;

$(2)$ increase the capacity of Operation $2$ by $10$ percent; or $(3)$ increase the capacity of Operation $3$ by $10$ percent?