The players on a basketball team made some three-point shots, some two-point shots, and some one-point free throws. They scored as many points with two-point shots as with three-point shots. Their number of successful free throws was one more than their number of successful two-point shots. The team's total score was 61 points. How many free throws did they make?
- A)
- B)
- C)
- D)
- E)
Answer
A
Key insight
Let y be the number of two-pointers; then three-pointers also contribute 2y points and free throws contribute y + 1, so 5y + 1 = 61.
Solution
Let be the number of two-point shots. They scored points from these, and the three-point shots produced the same number of points, . The free throws numbered , worth points.
Total score:
so . The number of free throws is .
(Check: two-pointers give points, three-pointers give points, free throws give ; total .)
The answer is .
Why this works
Everything is expressed in terms of one unknown because each condition ties another quantity to the number of two-point shots. Notice that the three-point shot count never needs to be found: the condition is about points, so " points" is all we use. Read whether a condition compares counts or points.
The trap
Setting the number of three-point shots equal to the number of two-point shots, instead of equating the points they scored.
Common mistakes
- Setting the number of three-point shots equal to the number of two-point shots, instead of equating the points they scored.
- Solving for and answering , forgetting the question asks for free throws, which is .
Techniques
Set up the equation/formula and compute; no special trick needed