SOLUTION: . The cost of petrol rises by 2 cents a liter. last week a man bought 20 liters at the old price. This week he bought 10 liters at the new price. Altogether, the petrol costs $9.2
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-> SOLUTION: . The cost of petrol rises by 2 cents a liter. last week a man bought 20 liters at the old price. This week he bought 10 liters at the new price. Altogether, the petrol costs $9.2
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Question 1117356: . The cost of petrol rises by 2 cents a liter. last week a man bought 20 liters at the old price. This week he bought 10 liters at the new price. Altogether, the petrol costs $9.20. What was the old price for 1 liter? Found 2 solutions by ikleyn, josgarithmetic:Answer by ikleyn(52921) (Show Source):
20x + 10*(x+2) = 920 cents, where x is old price in cents for 1 liter.
20x + 10x + 20 = 920
30x = 920-20
30x = 900 ====> x = = 30.
Answer. The old price for one liter of petrol was $0.30 per liter.
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