Problem Solving relevance filter
Relevant Selection questions give you extra numbers on purpose. Keep only the ones that change the answer.
The filter
- Write the quantity and unit the question asks for.
- Translate words like at least, remaining and maximum.
- Keep only numbers that would change that quantity.
- Check you found the requested quantity, not a nearby total.
| Question asks for | Usually needed | Often a distraction |
|---|---|---|
| Revenue | Quantities and prices | Costs and wages |
| Minimum journeys | Load and capacity | Fuel price and times |
| Earliest finish | Durations and dependencies | Costs |
Count letters, not patients
Worked example A mailing with two filters
A clinic has patients. use email. Of the rest, live in two-patient households and each household receives one shared letter. Everyone else receives one letter. Postage is pence per letter and the printer makes letters per minute. How many letters are needed?
Why this works: Count households only for the paired group. Postage and printer speed do not matter.
Why the tempting route fails: gives every postal patient a letter. forgets the shared letters.
Keep limits
A number can matter as a limit. An van capacity confirms one trip for a load. At it changes the answer.