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Priya's ride to the library — average speed
Priya cycles from her house to the library at 12 km/h and cycles back home at 8 km/h. The library is 24 km away. What is her average speed for the whole trip?
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The pattern behind it: An average is a total
Turn the average back into a total before doing anything with it.
In this one. Average speed is total distance divided by total time, not the average of the two speeds, because the slower return leg takes longer.
How to spot it
The word 'average' appears alongside a group being split into two parts, or two separate journeys or trips being combined into one overall figure.
Common mistake
Children average two averages directly, such as averaging two speeds or two group averages, without weighting by how many, or how long, each part actually covers.
Try one like it
Standard A bakery's week — average daily sales A bakery recorded its sales over 5 days: $42, $48, $55, $51 and $44. What was the average daily sales amount over the 5 days?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.
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