Final answer:
To calculate the number of bags of weed 'n' feed needed each year, divide the area of the garden by 15 and multiply by 8.67 to account for the recommended application rate and frequency.
Step-by-step explanation:
To calculate the number of bags of weed 'n' feed needed each year, we need to determine the total area of the garden and the frequency of applications.
Let's assume the garden has an area of A square meters.
The recommended application rate is 1kg over 15 square meters. Therefore, for an area of A square meters, we would need A/15 kg of weed 'n' feed for each application.
The application is repeated at 6-week intervals, so the number of applications in a year (assuming 52 weeks) would be 52/6 = 8.67 (rounded to the nearest whole number).
Therefore, the total amount of weed 'n' feed needed each year would be:
Total = (A/15 kg) x 8.67