Apple sold 95 laptops in 2018 and 80 laptops in 2019. Dell sold 90 laptops in 2020. What is the difference between the total number of laptops sold by Apple in 2018 and 2019 and the number of laptops sold by Dell in 2020?

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?