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Push Mower
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It takes 5 hours to complete the job
1 hour = 1/5 of the job
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Riding Lawn Mower
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It takes 3 hours to complete the job
1 hour = 1/3 of the job
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Push Mower + Riding Lawn Mower
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1 hour = 1/5 + 1/3
1 hour = 3/15 + 5/15
1 hour = 8/15 of the job.
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Calculate time needed to complete
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8/15 of the job takes 1 hour
8/15 of the job = 1 hour
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Divide by 8/15 on both side
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8/15 ÷ 8/15 of the job = 1 ÷ 8/15 hour
Whole of the job = 1 x 15/8 hours
Whole of the job = 15/8 hours
Whole of the job = 1 7/8 hours
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Answer: 1 7/8 hours
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check the picture below.
notice, a function that is decreasing, namely have a negative slope, doesn't have to be negative.
Starting with the paints, we have 15$ as our base value. Next, since we add $24.50 for each new canvas bought, 24.5*x=the amount of money for x canvases. Therefore, since 15 is our base value, we have 15+24.5*6=162
Cost of chicken wings at Buffalo Bills = 8 wings for $7
Cost of 1 wing at Buffalo Bills = 
Cost of chicken wings at Buffalo Mild Wings = 12 wings for $10
Cost of 1 wing at Buffalo Mild Wings = 
Cost of chicken wings at Wingers = 20 wings at $17
Cost of 1 wing at Wingers = 
Hence, comparing all the three costs per wing, we can see that Buffalo Mild Wings is serving chicken wings at lowest price of $0.833 per wing.