Here in this blog we are discussing about ADF – Interview Aptitude Questions – Payilagam – Part – VI . Some of them are :

1.In an inter school competition , the students have enrolled their names in various events . On a particular event , students of different ages have paticipated . The teacher found that the average age of 15 students was 15 years. Out of these, the average age of 5 students is 14 years and the average age of 9 students is 16 years. Find the average age of the 15th student .

HINT :          Average =             Sum of the observations
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Total number of the observations

Sum of the observations = Average x Total number of the observations

SOLUTION :

Given, the average age of 15 students = 15 years

=> Sum of the ages of 15 students = 15 x 15 = 225

Average age of 5 students = 14 years

=> Sum of the ages of 5 students = 5 x 14 = 70

Average of other 9 students = 16 years

=> Sum of the ages of 9 students = 9 x 16 = 144
Hence the age of the 15 th student = ( 15 x 15 ) – [ ( 5 x 14 ) + ( 9 x 16 ) ]

= 225 – ( 70 + 144 )
= 225 – 214 = 11 years

Thus the age of the 15 th student is 11 years.

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2. The average monthly income of Nila , Arya and Diya was Rs. 40,000 . The average monthly income of Arya and Diya was Rs. 30,000 and the average monthly income of Nila and Diya was Rs.50,000 . Then what is the monthly income of Diya

HINT :                    Average =        Sum of the observations
——————————————–
Total number of the observations

Sum of the observations = Average x Total number of the observations
SOLUTION :
Average monthly income of Nila , Arya and Diya = Rs . 40,000

=> Sum of the monthly income of Nila , Arya and Diya = 3 x 40,000 = 1,20,000

Average monthly income of Arya and Diya = Rs . 30,000

=> Sum of the monthly income of Arya and Diya = 2 x 30,000 = 60,000

Average monthly income of Nila and Diya = Rs . 50,000

=> Sum of the monthly income of Nila and Diya = 2 x 50,000 = 1,00,000
Then the monthly income of Diya = [(2 x 30,000)+(2 x 50,000)] – (3 x 40,000)

= [ 60,000 + 1,00,000 ] – 1,20,000

= 1,60,000 – 1,20,000

= 40,000

Thus the monthly income of Diya is Rs . 40,000

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