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A trader buys some eggs at 6naira each. She finds out that six of them are broken,
she sells the rest at 10naira each and makes a profit of 160. How many eggs did she buy?
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Let n be the number of eggs she bought.
Then we have this equation
Profit = Revenue - Cost;
Profit = 160; Cost = 6n; Revenue = 10*(n-6);
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| 160 = 10*(n-6) - 6n. |
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Simplify it
160 = 10n - 60 - 6n
160 + 60 = 4n
220 = 4n
n = 220/4 = 55.
ANSWER. She bought 55 eggs.
CHECK, 10*(55-6) = 10*49 = 490; 6n = 6*55 = 330; 490 - 330 = 160 (profit). ! Correct !
Solved.