The miller wants to bake a loaf of bread, but he didnt have any flour. he decided to grind just enough for eight loaves. if it takes one and three fourths kilograms of flour for two loafs, how much flower will he need?

The miller needs 1-3/4 kg (or  1.75 kg) for two loaves.
Therefore the amount of flour needed for 1 loaf is
1.75/2 = 0.875 kg per loaf.

For 8 loaves, the amount of flour needed is 
8*0.875 = 7 kg

7 kg of flour is needed for 8 loaves.