Answers

2015-01-09T12:11:05+05:30
Let no. of correctly solvd questions b x n those of incorrect b y
so x + y = 85
5x - 2y = 285
on solving these equations u'll get x = 65 
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show how to solve equation
cn u plz solve d 1 vch I'v posted?? i need it urgnt..
x + y = 85 so y = 85 - x
5x - 2(85 - x) = 285 5x - 170 + 2x = 285 7x - 170 = 285 7x = 455 x = 65
2015-01-09T18:51:46+05:30
no of questions answerd=x
no of questions which are incorrect=y
so  as  per the question
x + y = 85 (1)
5x - 2y = 285(2)
from one y =85-x (3)
by substitution equation 3 in 2 you get
5x-2 (85-x)=285
5x-170+2 x=285
7x=285+170
7x=455
x=65
so no  of correct answers =65
and no of incorrect answer =85-65
                                         =20

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