The average salary, per head, of all the workers of an institution, is Rs. 60. The average salary of 12 officers is Rs. 400; the average salary, per head, of the rest is Rs. 56. The total number of workers in the in situation is 

Direction : What should come in place of the question (?) in the following question.

(41) ² + (38)² × (0.15)²=?

A, B and C invested amounts in the ratio 3 : 4 : 5 respectively. If the schemes offered compound at the rate of 20 % per annum, 15 % per annum and 10 % per annum respectively, then what will be the ratio of their amounts after 1 year? 

By selling 66 metres cloth, a man loses S.P. of 11 metres. What is the loss percent?

If a-6b = 3 then the value of a³-216b³-54ab is : 

Read the following graph carefully and answer the related questions-

Total number of students (in thousands) participating in comitative exam in various cities.

What is the average number of students appearing in competitive exam from all the states together? 

Due to a 25% increase in the price of rice per kg. a person is able to purchase 20 kg. less for Rs.400. What is the increased price of rice per kg.?