Respuesta :
Answer:
170
Step-by-step explanation:
given:
Ann, Ben, and Cindy were eating strawberries.
The ratio of the numbers of berries they ate is 5:5:7.
If Cindy ate 30 strawberries less than Ann and Ben together,
find:
what is the total number of strawberries the three of them ate?
solution:
add the ratios 5 + 5 + 7 = 17
since Cindy ate 30, less than Ann and Ben together so, the equation is
7x = 5x + 5x - 30
7x - 10x = -30
x = 30/3
x = 10
ann 5 x 10 = 50
ben 5 x 10 = 50
cindy 7 x 10 = 70
total = 170
Answer: 170
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Explanation:
A = number Ann ate
B = number Ben ate
C = number Cindy ate
Let x be some positive whole number
Since A,B,C is in the ratio 5:5:7, this means
A = 5x
B = 5x
C = 7x
Note how A:B:C = 5x:5x:7x = 5:5:7. We divide all parts by x to simplify the ratio.
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Cindy ate 30 strawberries less than Ann and Ben, so
C = A+B-30
C = 5x+5x-30
C = 10x-30
Earlier in the last section we had C = 7x, and now we found C = 10x-30
Since we're talking about the same C value, we can equate and solve
C = 7x
10x-30 = 7x ... replace C with 10x-30
10x-7x = 30
3x = 30
x = 30/3
x = 10
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With this x value, we now know that...
A = 5x = 5*10 = 50
B = 5x = 5*10 = 50
C = 7x = 7*10 = 70
Cindy's count (70) is 30 less than Ann and Ben's combined count (50+50 = 100), so that helps confirm the answer.
Further confirmation comes from 50:50:70 reducing to 5:5:7 when you divide all parts by the GCF 10.
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The last step is to add the values of A, B and C.
A+B+C = 50+50+70
A+B+C = 100+70
A+B+C = 170
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Side note: since A+B+C = 5x+5x+7x = 17x, this means that the final answer is a multiple of 17.