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After striking a floor a rubber ball rebounds 5/6 th of the height from which it has fallen. Find the total distance (in metres) that it travels before coming to rest,if it gently dropped from a height of 210 metres.

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The first drop is 210 metres. After this the ball will rise by 175 metres and fall by 175 metres which is  5/6 th of 210 .

This process will continue in the form of infinite GP with common ratio 5/6 and first term 175.

The required answer is given by the formula:
a/(1-r) 

that is 175/(1 - 5/6) = 1050 metres.

Hence, 1050 metres is the answer.

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