Easy peasy.
A man agrees to work for $9per day. However, if he doesn't turn up at work on any day he will be penalised $6 per day.
At the end of thirty days, the workman is owed nothing.
How many days did he work?
I'm not sure how to even approach that one, except by trial and error. Can't figure out Mark's answer
Maybe Mark is setting another puzzle?
I reached the answer, but like JJB, by trial and error. Never been good at algebra.
I didn't use algebra to solve it - not knowingly anyway!!
I got the same answer as Mark, but I think I went about it a different way. I didn't find it difficult to come up with an equation to describe the situation, but I really struggled to then solve that equation for x because I'm so rusty! In the end, I had to plug numbers into my equation as I just couldn't solve it any other way! I suspect I may have made it more difficult for myself than I needed to.
Here's my working, if anyone is interested/wants to point out where I went wrong:
We were looking for number of days worked, so I called that x
Pay for days worked = 9x
Days not worked = 30 - x
Pay deducted = 6(30 - x)
So 9x - 6(30 - x) = 0
Solve for x
9x = 6(30 - x) - I added 6(30 - x) to both sides
9x/(30-x) = 6 - I divided both sides by 30-x
Then I tied myself in knots and couldn't remember how to get any further!
I knew x had to be a number between 1 - 30, so I then plugged numbers in and used how close they were to giving me 6 in that equation to work out how far off I was.
If he works 2 and then has a rest for 3, he gets nothing for 5 days.
There are 6 periods of 5 days in 30 so he must work 5 x 2 days =12