If a rubber ball consistently bounces back $$\frac{{2}}{{3}}$$ of the height from which it is dropped, what fraction of its original height will the ball bounce after being dropped and bounced four times without being stopped?
A. $$\frac{{16}}{{81}}$$
B. $$\frac{{16}}{{27}}$$
C. $$\frac{{4}}{{9}}$$
D. $$\frac{{37}}{{81}}$$
Answer: Option A
Solution(By Examveda Team)
Each time the ball is dropped and it bounces back, it reaches $$\frac{{2}}{{3}}$$ of the height it was dropped from.After the first bounce, the ball will reach $$\frac{{2}}{{3}}$$ of the height from which it was dropped - let us call it the original height. After the second bounce, the ball will reach $$\frac{{2}}{{3}}$$ of the height it would have reached after the first bounce.
So, at the end of the second bounce, the ball would have reached $$\frac{{2}}{{3}}$$ × $$\frac{{2}}{{3}}$$ of the original height = $$\frac{{4}}{{9}}$$ th of the original height.
After the third bounce, the ball will reach $$\frac{{2}}{{3}}$$ of the height it would have reached after the second bounce.
So, at the end of the third bounce, the ball would have reached $$\frac{{2}}{{3}}$$ × $$\frac{{2}}{{3}}$$ × $$\frac{{2}}{{3}}$$ = $$\frac{{8}}{{27}}$$ th of the original height.
After the fourth and last bounce, the ball will reach $$\frac{{2}}{{3}}$$ of the height it would have reached after the third bounce.
So, at the end of the last bounce, the ball would have reached $$\frac{{2}}{{3}}$$ × $$\frac{{2}}{{3}}$$ × $$\frac{{2}}{{3}}$$ × $$\frac{{2}}{{3}}$$ of the original height = $$\frac{{16}}{{81}}$$ of the original height.
Related Questions on Progressions
Find the first term of an AP whose 8th and 12th terms are respectively 39 and 59.
A. 5
B. 6
C. 4
D. 3
E. 7
The sum of the first 16 terms of an AP whose first term and third term are 5 and 15 respectively is
A. 600
B. 765
C. 640
D. 680
E. 690
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