He spend: 1440*2.5=3600
he earn: 0.25*1440*12=4320
[because he sells 0.25/each and buy 1440 dozen so 1440*12]
4320-3600=720
Answer:
The answer is -1\4
Step-by-step explanation:
because its negative you can't expect it to be positive 1\4 and its the only one that made sense
Let X and Y be the digits.
If a two-digit number is written XY, then its value is 10x+y.
When the digits of the number are interchanged, it's YX, and its value is 10y+x.
The sum of the digits is 12.
The number formed by interchaning the digits is 54 more than the original number.

The digits X and Y are 3 and 9, so the original number is 39.
I set it up as a ratio with hours on the top and the fraction of the job on the bottom. It looks like this: 5/(2/3) / x/1, because 1 is the whole job if 2/3 is only a fraction of it. Cross multiplying gives you 2/3x = 5. Solving for x gives you that it will take 7.5 hours to complete a whole job if it takes 5 hours to complete 2/3 of it.