The average age of 30 students is 9 years. If the age of their teacher is included, the average age becomes 10 years. The age of the teacher (in years) is :
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The average of X1, X2 and X3 is 14. Twice the sum of X2 and X3 is 30. What is the value of X1?
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The average age of the mother and her six children is 12 years which is reduced by 5 years if the age of the mother is excluded. How old is the mother ?
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If the arithmetic mean of 0, 5, 4, 3 is a, that of 1, 0, 1, 5, 4, 3 is b and that of 5, 4, 3 is c, then the relation between a, b, and c is
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The mean of 25 observations was found to be 78.4. But later on it was found that 96 were misread as 69. The correct means is
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Find the average increase rate, if increase in the population in the first year is 30% and that in the second year is 40%.
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There are 30 students in a class. The average age of first 10 students is 12.5 years. The average age of the remaining 20 students is 13.1 years. The average age (in years) of the students of the whole class is :
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The average age of 20 boys in a class is 12 years. 5 new boys are admitted to the class whose average age is 7 years. The average age of all the boys in the class becomes:
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If the average of 5 consecutive integers is x then, find the average of next to next 5 consecutive integers.
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The average of six number is x and the average of three of these is y. the average of the remaining three is z, then
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The speed of the train going from Nagpur to Allahabad is 100 km/h while when coming back from Allahabad to Nagpur, its speed is 150 km/h. find the average speed during whole journey.
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