Seeding the backyard
In order to find how many boxed they need, first they need to know the area they will have to cover:
In order to find it, we have find the total area of the rectangle and take off the area of the House and the area of the shed:
We know that all those areas are rectangles, their area are found multiplying their sides lenght:
House area = 5m x 16m = 80m²
Shed area = 3m x 3m = 9m²
Since the lateral side of the total area is
5m + 16m + 5m = 26m, then
Total area = 26m x 50m = 1300m²
Then, the area they need to cover is
total area - house area - shed area = 1300m² - 9m² - 80m²
= 1211m²
Since the seed they select covers 375 m² per box, in order to find how many boxes they need, we just need to divide the area they are going to cover with this number:
1211m² ÷ 375 m² = 3.229
We round it to 4 boxes as indicated.
Answer: they need to buy 4 boxes of seeds