The first one is correct I think.
Andrea had 5 coins worth 50 cents ! And , thereafter her brother gave her 7 coins worth 23 cents .
<u>Step-by-step explanation:</u>
Here we have , Andrea has some money. Her brother gives her 7 coins worth 23 cents and now she has 73 cents. If she started with 5 coins, We need to find what coins did Andrea's brother give her and what coins did Andrea start with. Let's find out:
Andrea has some money , and her brother gives her 7 coins ! worth 23 cents . So , 1 coin worth is :
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Now , she had a total of 73 cents i.e.
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Initially Andrea had 5 coins worth 50 cents ! And , thereafter her brother gave her 7 coins worth 23 cents .
510 = (1700)(6)(t)
510 = 10200t
0.05 = T