Maya, Madhura and Mohsina are friends studying in the same class. In a class test in geography, Maya got 16 out of 25. Madhura got 20. Their average score was 19. How much did Mohsina score?
Answers
Answer:
formula to be implemented =
mean = sum of all observation/ total no.of observation
=> maya s score given = 16
=> madhura score given = 20
=> mohsina score given = lets consider as unknown value a
=> average score they scored together= 19
=> So we will implement the above formula as its the formula to calculate the average in arithmatic mean.
=> mean = sum of all observation/
total no. of observation
=> So we will subsitute the values or replace the actual values instead of formula.
=> 19 = 16 + 20 + a / 3( we wrote 3 because we should write total numbers given as numerator )
=> 19 = 36 + a / 3
=> 19 x 3 = 36 + a / 3 x 3 ( on LHS we will
multiply and on RHS we
will cancel the 3 )
=> 57 = 36 + a
=> 57 - 36 = a ( transposition, when we bring + 36 to LHS then it will turn negative if 36 would have been negative -36 then it would turn positive and have been added with 57 )
=> 21 = a
Now if we do the verification,
then,
=> 16 + 20 + 21/3
=> 36 + 21/3
=> 57/3
=> 19
So our answer is correct...hope it helps you
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