In 1 hour you pick 60 lines, so in 8 hours you pick 60*8 = 480 lines
It is given in the question that
Anna buys 12 pens and 20 pencils for a total cost of $16. One pen costs $0.40 more than a pencil.
Let the cost of pencil is $ x .
Therefore cost of pen is

According to the question

Distributing 12 and combining like terms, we will get

Therefore cost of pencil is $0.35 and cost of pen is

The final answer to tour problem 16.3
My initial answer was $2750.45, and I will show you my calculations.
Calc : 6774.5 ÷ 100 = 67.745
67.745 × 2.7 = 182.9115
182.9115 × 22 = 4024.053
6774.5 - 4024.053 = 2750.45
= $2750.45
At first I thought this was correct, but after studying my answer I realise that the amount of interest would rise as the amount of money went up, therefore my calculations are very wrong. If I work out the answer, I will get back to you, but the calculation is more complicated than I first predicted