The second one because there is all the inputs are different. There is one input for every output.
        
             
        
        
        
Answer:
40 girls
Step-by-step explanation:
if you multiply 5 times 10, then you have to multiply the other side by 10 too. So 5 times 10 equals 50, and 4 times 10 equals 40. 
40+50+=90.
 
        
             
        
        
        
<span> 2ab + 2bc + 2ac the formula for the rectangular prism and i'm guessing you would find the answer to this than you would find your formula for the cube which is </span><span><span>6 a </span>2 and you would find that answer. 
</span>You would take your total for the rectangular prism answer and subtract the cube answer from it and you would probably get your answer. 
hope that helped?!
:)
 
        
        
        
5 packs of erasers and 3 packs of pencils each will have 60