Suraj0184 wrote:
John and Jack are among 10 students who write an examination. John scored 80 marks. The average score of the 8 students other than them is 72.5. The average score of all the 10 students is one more than the average score of the 9 students other than John. The score of Jack is
A. 40
B. 45
C. 50
D. 55
E. 60
(Source :Wizako)
John = 80
The other 8 = 72.5*8 =580
\(\frac{80+580+Jack}{10} =\frac{580+Jack}{9}+1\)
\(\frac{660+Jack}{10} =\frac{580+Jack+9}{9}\)
\( 5940+9Jack =5890+10Jack\)
\( 50 =Jack\)
Answer choice C.
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