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370 visitors — who bought a raffle ticket
A charity fun fair had 370 visitors, made up of children and adults. of the children and of the adults bought a raffle ticket. The number of children who did not buy a raffle ticket is twice the number of adults who did not buy one. How many adults did not buy a raffle ticket?
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65 worked examples are free without a code, two from every pattern. No account, either way.
The pattern behind it: The equal concept
The question tells you a part of one pile equals a part of another.
In this one. Make the numerator the same. The matching numerator 6 makes one group on each side the same size; then the denominator gives the total number of same-sized units, so children : adults = 27 : 10.
How to spot it
Two different groups each get their own fraction or percentage, and the question links them with 'the same as', 'twice as many as', or a shared cost across different units.
Common mistake
Children compare the two fractions without first relating them to a common whole. A smaller fraction of a larger group can be bigger than a larger fraction of a smaller group.
Try one like it
Challenging 810 workers — who finished on time A factory has 810 workers, made up of assembly-line workers and packing workers. 7/12 of the assembly-line workers and 8/9 of the …The 33 problem patterns
All 33 patterns, one to a page — the 19 behind Primary 5 and 6 word problems, and the skills the younger years are built on. The bar model, how to spot it in the question, and the mistake children make. A booklet you can print. Free.
A PDF, and a note when new solutions go up.