2. Alana needs to sell 52 boxes of cookies:
She sold 7 boxes to her aunt
She sold 2 boxes to her mother
She sold 15 boxes to her neighbor 
you add 7+2+15 = 24 boxes of cookies that she sold
We need to find out how many more boxes of cookies she needs to sell-
We take the 24 boxes she sold and subtract from 52 boxes that she needs to sell.
24 - 52 = 30
The answer is 30, she needs to sell 30 more boxes.
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3.  Sam, Jimmy and Andre shared a number of pennies in the ratio 8:5:3
Sam (8), Jimmy (5) and Andre (3)
How many more pennies did Jimmy receive than Andre?
you subtract 3 - 5 = 2 
The answer is 2 more pennies.
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4. Jamila spent $33.00 and Akiko spent $ 42.00  
Jamila  had 4 times as much money left as Akiko. How much money did each of them have in the beginning?
Since Akiko spent the highest amount- you will have to go with the higher amount to find the answer 
4 x $42.00 = $168.00 
They both in the beginning had $168.00
I hope this helps.