PSLE Oliver threw a ring around the top of a bottle 20 times. One point was scored when the ring fit on the bottle and one point was deducted when the ring bounced off the bottle.
For Oliver's first 13 throws, the ring fit on the bottle 6 times.
- What was Oliver's score from the first 13 throws?
- At the end of 20 throws, Oliver's scored 3 points. How many successful throws did he make for his last 7 throws?
(a)
Number of misses
= 13 - 6
= 7
Number of points scored = 6
Oliver's score
= 6 - 7
= -1
(b)
Oliver's score for the last 7 throws
= 3 - -1
= 4
If Oliver made 7 successful throws, the score he earned = 7
If Oliver made 6 successful throws, the score he earned
= 6 - 1
= 5
If Oliver made
5 successful throws, the score he earned
= 5 - 1
= 4
Since Oliver's score for the last 7 throws was
4, he made 5 successful throws.
Answer(s): (a) -1; (b) 5