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1. The average of five weights is 13 grams. This set of five weights is then increased by another weight of 7 grams. What is the average weight of the six weights?

2.From a pile of 100 pennies(P), and 100 nickels(N), and 100 dimes(D), select 21 coins which have a total value of exactly \$1.00. How many coins of each of the three types (P,N,D) should be selected?

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If the average weight of 5 is 13, then multiply 5x13=65. Add 7 to get 72. Then divide by the new total of 6 to get 12.

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5 p, 11n, 5d
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uh... no.

Unless the avg is 13 grams PER weight. But the way it is worded it is a total of 13.

Them it depends on the way it is written.
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5p 11n 5d?

wow... 21 coins but adds up to \$1.10
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You're right on that one. 10 p, 4 n, 7 d is correct
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Thank you very much I really appreciate it.
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Anytime!
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13+7=20/6= 3 1/3Just add the extra weight and divide by total...

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Um, yes! It says the AVERAGE o f 5 weights, thus giving you an aggregate total of 65 grams. Add another weight of 7 grams, & your total is 72 grams. That divided by the 6 weights gives you a new average of 12 grams. Simple math. No strange wording. Do your homework
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Thank you for the equation. It really helped.
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