A kilogram of flour costs 6$. How much does 400 grams of flour cost?

Question

This is a problem in my math workbook, thanks for helping

Answer 1

1 kilogram = 1000 grams

Therefore 1000 grams = $6

 

From here, we can set up a ratio problem:

^$6/_{1000 grams} = ^x/_{400 grams}

 

Multiply both sides by 400:

^{$6 * 400 grams}/_{1000 grams} = x

We can easily factor out 100 and the grams:

^{$6 * 4}/₁₀ = x

Heck, we can even factor out another 2:

^{$6 * 2}/₅ = x

I'm sure you can solve for x from here.