Q.211- The average of nine number is 50. The average of first five numbers is 54 and that of the last three numbers is 52. Then the sixth number is :
Q.212- From a class of 42 boys, a boy aged 10 years goes away and in his place, a new boy is admitted. If on account of this change, the average age of the boys in that class increases by 2 months, the age of the newcomer is :
Q.213- The average of 30 numbers is 40 and that of other 40 numbers is 30. The average of all the numbers is :
Q.214- A man purchased 7 bags of rice at the rate of Rs. 800 each, 8 bags of rice at Rs. 1000 each and 5 bags of rice at the rate of Rs. 1200 each. What is the average cost of one bag of rice ?
Q.215- The sum of three consecutive even numbers is 28 more than the average of these three number. Then the smallest of these number is –