Mathematics MCQs Police Department PPSC Past Papers Sub Inspector (SI)

The average of 5 quantities is 6. The average of 3 of them is 4. What is the average of remaining 2 numbers?

  • 9
  • 9.5
  • 10
  • 11
  • a
  • average=Sum of observation/no of observation6= sum of observation/5so sum of observation= 30so sum of three + sum of two observation= 30so (4*3)+sum of two observation= 30sum of two observation= 30-12=18so it's average= 18/2= 9so 9 is answer

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Mathematics MCQs Police Department PPSC Past Papers Sub Inspector (SI)

Average age of A and B is 30 Years, that of B and C is 32 Years and the average age of C and A is 34 Years. The age of C is:

  • 36
  • 38
  • 40
  • 42
  • a
  • Average of A & B is 
    ( A+B) /2 = 30  ⇒ A+B=60 ⇒ A= 60 – B —- (i) 
    ( B+C)/2 = 64 ⇒B+C = 64 ⇒ B= 64 – C—- ( ii ) 
    Putting value of B in equation ( i ) 
    ⇒ A= 60 – 64 +C ⇒ A = -4 + C —– ( iii) 
    ( C+A)/2 = 34  ⇒ C+A=68 ⇒ C = 68 – A —–(iv)
    Puuting value of A from eaquation ( iii) to eq. (iv)
    ⇒ C= 68 +4 -C ⇒ C =36

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