Answer:
There were 35 gallons of gasoline and 500 gallons of kerosene.
Explanation:
Step 1: Write data for equation 1
Let gallons of kerosene be x
Let gallons of gasoline be y
Total capacity of truck is 4000
Step 2: Form equation 1
x + y = 4000
Step 3: Write data for equation 2
Profit of total gallons of kerosene is 0.12x
Profit of total gallons of gasoline is 16y
Total profit is $620
Step 4: Form equation 2
0.12x + 16y = 620
Step 5: Find x in terms of y from equation 1
x + y = 4000
x = 4000 - y
Step 6: Substitute value of x in equation 2
0.12x + 16y = 620
0.12 (4000 - y) + 16y = 620
480 - 12y + 16y = 620
4y = 620 - 480
y = 140/4
y = 35
Step 7: Substitute value of y in equation 1 to find x
0.12x + 16y = 620
0.12x + 16 ( 35 ) = 620
0.12x = 60
x = 500
There were 35 gallons of gasoline and 500 gallons of kerosene.
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