26june2019 paper1 Q20

20The average of 35 raw scores is 18. The average of first seventeen of them is 14 and that of last seventeen is 20. Find the eighteenth raw score.

Option : C
Explanation : Sum of scores of all 35 raw scores
=35 x 18 = 630
Sum of scores of first seventeen
=17 x 14 = 238
Sum of scores of last seventeen
=17 x 20=340
Hence, eighteenth raw score
= -238 - 340 + 630 = 52

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