A bag contains 7 blue balls and 5 yellow balls. If two balls are selected at random, what is the probability that none is yellow?

What is the average number of petrol engine cars in all the states together? 

What is the difference between the total number of cars in State-3 and the number of petrol engine cars in State-2?

If 95% of diesel engine cars in State-3 are AC and the remaining cars are non AC, what is the number of diesel engine cars in State-3 which are non-AC?

The number of petrol engine cars in State-3 is what percent more than the number of diesel engine cars in State-1?

What is the difference between the number of diesel engine cars in State-2 and the number of petrol engine cars in State-4?