To receive grade A in a cource, one must obtain an average of 90 marks or more in five papers each of 100 marks. If Shikha scored 87, 95, 92 and 94 marks in first four papers find the minimum marks that she must score in the last paper to get grade A in the course.

Explanation

Let `x` be the minimum marks scored in the last paper.
Then,

`90 leq frac{87+95+92+94+x}{5} leq 100`

`Rightarrow 90 leq frac{368+x}{5} leq 100 `

`Rightarrow 450 leq 368+x leq 500`

`Rightarrow 450-368 leq 368+x-368 leq 500-368 `

`Rightarrow 82 leq x leq 132`


But `x` can not be more than `100`

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