At the greenhouse where you work you need to make soil and vermiculite mixtures for potting plants. Flowering bushes need a mixture of 70% soil and...

Flowering bushes need a mixture of 70% soil and 30% vermiculite by volume. So if we simplify this it means to we need 30 buckets of vermiculite to mix with 70 buckets of soil.

Vermiculite needed to 70 buckets of soil `= 30`

Vermiculite needed to 1 buckets of soil   `= 30/70`

Vermiculite needed to 5 buckets of soil  `= (30/70)xx5 = 2.143`

So we need 2.143 buckets of vermiculite to mix with 5 buckets of soil. How ever we can measure two buckets easily. For the rest 0.143 bucket, it is a volume close to 1/6 of the total volume of the bucket.