The table shows how much a worker is paid each day.

1st hour	$75
Every additional hour	$40
For every 4 hours of completed work, an additional $10 will be paid.

Mr Morris was paid $325 for a day's work. How many hours did he work? Answer: ___ h

1. Subtract the pay for the 1st hour from the total pay

Pay remaining after 1st hour = $\char36{}325 - \char36{}75 = \char36{}250$

2. Determine the pay structure for subsequent hours

For every additional hour, the pay is $\char36{}40$.
However, for every 4 hours of completed work, there is an additional $\char36{}10$.
Let's check the pay for the first 4 hours of work:
1st hour: $\char36{}75$
Next 3 hours: $3 \times \char36{}40 = \char36{}120$
Bonus for 4 hours: $\char36{}10$
Total for 4 hours = $\char36{}75 + \char36{}120 + \char36{}10 = \char36{}205$

3. Calculate the remaining pay and hours after the first 4 hours

Remaining pay = $\char36{}325 - \char36{}205 = \char36{}120$
Since each additional hour (before reaching the next 4-hour block) pays $\char36{}40$, the number of additional hours is:
$\char36{}120 \div \char36{}40 = 3$ hours.
Total hours worked = $4 + 3 = 7$ hours.
(Check: 7 hours is not a multiple of 4, so no second bonus is triggered. Total pay = $\char36{}75 + 6 \times \char36{}40 + \char36{}10 = \char36{}75 + \char36{}240 + \char36{}10 = \char36{}325$. This matches.)