In a game of 100 points, A can give 20 points to B and 28 points to C. How many points can B give C?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 10 points
When A scores 100, B scores 100 − 20 = 80 and C scores 100 − 28 = 72.
\( \displaystyle \frac{C}{B}=\frac{72}{80} \)
When B scores 100:
\( \displaystyle C=\frac{72}{80}\times 100=90 \)
So B can give C 100 − 90 = 10 points.
Tip: Do not simply subtract 28 − 20 = 8: the scores must be scaled so that B reaches 100.