One tank of gasoline has an octane rating of 140 and another tank of gasoline has an octane rating of 80. to obtain a mixture of 60 gallons with an octane rating of 120, how many gallons should be used from the tank with the octane rating of 80?

Question

Chemistry

Ricky Bates

13 January, 02:23

One tank of gasoline has an octane rating of 140 and another tank of gasoline has an octane rating of 80. to obtain a mixture of 60 gallons with an octane rating of 120, how many gallons should be used from the tank with the octane rating of 80?

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Answers (1)

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Lesly Leon · Answer 1

Call x the volume of gas whose octane rating is 140 and y the volume of gas whose octane rating is 80, then:

(1) x*140 + y*80 = 60*120, and

(2) x + y = 60

from (1) 140x + 80y = 7200 = > (3) 7x + 4y = 360

from (2) - - - > (4) 4x + 4y = 240

Subtract (4) from (3)

7x - 4x = 360 - 240

3x = 120

=> x = 120/3 = 40

=> y = 120 - 40 = 80

Answer: should be used 80 gallons from tank with the octane rating of 80