If qr = 3 c of charge moves to the right in tr = 2.0 s while ql = -625 mc of charge moves to the left in tl = 4.5 s , what is the net current to the right

I=dQ/dt 
 ir = 3C/2.0s = 1.5A ;; current due movement of charge Qr 
 il = -0.625C/4.5s = -0.138 A ;; current due movement of charge Ql 
 to find net current you need to establish some references such as reference direction, and time. 
 for example if both charges start moving at the same time and positive current direction is to the right then: 
 iNet = ir + il ;; but we need to observe direction convention so... 
 iNet = ir + il = 1.5A + (-0.138 A) = 1.361 A