TARA · Problem Solving
TARA finding procedures questions
Work out a method from the information given and carry it through to a number.
How to spot it
- How many ...?
- What is the smallest number of ... for which ...?
Try one
Original example
A school hall has 14 rows of chairs with 22 chairs in each row. For a concert, the front 2 rows are kept for staff, and 3 chairs are removed from each of the other rows to widen the aisle.
How many chairs are left for the audience?
The method
- Write what you know and what you need.
- Build the steps in order, writing each result down.
- Check the edge: "cheaper than" is not "the same as".
The trap
Watch forStopping at the point where two things are equal when the question asks when one beats the other.
Now a harder one
Harder
Ana's phone plan costs £8 a month plus 5p for each text over 100 in that month. Ben's plan costs £12 a month with unlimited texts.
What is the smallest number of texts in a month for which Ben's plan is cheaper than Ana's?