Mixture word problems, step by step

Two things at two prices, poured into one bag: what does the blend cost?

The question

What is the price per kg of the blend?

A store blends 2 kg of milk chocolate at $36 a kg with 4 kg of dark chocolate at $54 a kg.
2 × 36 + 4 × 54 = 288
2 × 36 + 4 × 54 = 288
288 ÷ 6 = $48
asked:What is the price per kg of the blend?
$48
  1. Read it through once. Two things at DIFFERENT rates are combined. You cannot just average the two rates — the bigger amount pulls the blend toward its own rate, so each rate has to be WEIGHTED by how much of it there is.
  2. Weight each amount by its rate and add them up: 2 × 36 + 4 × 54 = 288. That is the total spread across the whole mixture.
  3. Now divide that total by how much there is altogether: 288 ÷ 6 = $48.
  4. Answer the question that was asked — "What is the price per kg of the blend?" — $48.

How it works.

  1. 01

    Read it through once. Two things at DIFFERENT rates are combined. You cannot just average the two rates — the bigger amount pulls the blend toward its own rate, so each rate has to be WEIGHTED by how much of it there is.

  2. 02

    Weight each amount by its rate and add them up: 2 × 36 + 4 × 54 = 288. That is the total spread across the whole mixture.

  3. 03

    Now divide that total by how much there is altogether: 288 ÷ 6 = $48.

  4. 04

    Answer the question that was asked — "What is the price per kg of the blend?" — $48.