A coin purse holds 25 coins, all ₱5 and ₱10 coins, worth ₱175 in total. How many ₱10 coins are there?
Correct answer: B. 10
Let t be the number of ₱10 coins: 10t + 5(25 − t) = 175, so 5t + 125 = 175 and t = 10. Check: 10 coins × ₱10 + 15 coins × ₱5 = ₱100 + ₱75 = ₱175.
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