Ratios: find one part when you know the total
Add the parts of the ratio to find the number of equal parts in the whole, then work out one group.
Loading a question…
You've done today's 10 free questions.
Come back tomorrow for 10 more, or get unlimited practice with a membership.
Want more today? Print 20 more questions free, with the answers.
Already a member? Sign in.
See worked examples
The ratio of cats to dogs is 1 : 3. There are 20 pets in all. How many dogs are there?
Answer: 15
The ratio of guitars to drums is 4 : 1. There are 10 instruments in all. How many guitars are there?
Answer: 8
The ratio of pencils to pens is 2 : 4. There are 12 writing tools in all. How many pens are there?
Answer: 8
Tip: Add the parts of the ratio to find the number of equal parts in the whole, then work out one group.
Print a worksheet of this skill New questions and an answer key, free.
Up next
- Next in this topic Ratios: find the other group when you know one count Grade 6
- Ready for more Ratios: find the other quantity Grade 7
Print a free worksheet with answers (20 questions).
Learn it hands-on
- Mix It, Pace It: Ratio, Rate and Percent Grades 6–7 · printable lessons
Practise without limits
Members practise as much as they like, every day, and get the printable packs and lessons too.