The performance of 1800 students across different grades is represented in a pie chart. In which two grades taken together is the total number of students exactly 54 less than the combined number of students in grades B and E?

In a data table, the production of rice for country Q and country R is 60 lakh tons and 54 lakh tons respectively. The production of wheat for country S and country T is 52 lakh tons and 52 lakh tons respectively. What is the ratio of the total production of rice of countries Q and R to the total production of wheat of countries S and T?

In a survey of 5 countries (P, Q, R, S, T), the rice production values are 40, 60, 54, 70, and 51 lakh tons respectively. What is the average production of rice (in lakh tons) across all 5 countries?