A lawn fertilizer recipe uses ammonium sulphate, iron sulphate and sharp sand in the ratio 3 : 1 : 20. 100 grams of fertilizer are needed for each square meter of lawn.
a) How much ammonium sulfate is needed to make 100 g of fertilizer?
b) Dave's lawn is a rectangle, 4 m long and 9 m wide. How much sharp sand does he need to fertilize his lawn?

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Answers

2016-03-02T11:11:19+05:30
    Ammonium Sulphate : Iron Sulphate : Sharp Sand
→ 3 : 1: 20

Ammonium Sulphate =  3x
Iron Sulphate = 1x
Sharp Sand = 20x

Total quantity = 100 gm

3x + 1x + 20x =  100
24x = 100
x = 100/24
   = 4.16 gm

a) Quantity of Ammonium sulphate = 3(4.16) gm
                                                    = 12.48 gm

b) Quantity of Sharp Sand/ 100 gm = 20(4.16)
                                                      = 83.2 gm

Area of lawn = 4(9) m²
                      = 36 m²

Quantity of Sharp Sand = 36(83.2) gm
                                      = 2995.2 gm



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