If the time in a distance/time graph is written like '12 noon' and '1pm' etc and not like 30 minutes, 40 etc how do we calculate the average speed then? divide the distance by what kind of time?

the first step is making objective observations.

they have to be based on a certain event and can be confirmed by others if it is right or not.

the entire statement is true and correct.  

there's no diagram, nothing is illustrated, and no question is asked.

answer: at 24 february, 2014 the population gets twice of its initial population.

explanation:

since we have given that

the population for alpha city, t years after january 1, 2004 is given as

first we find out the initial population, i.e. t=0,

so, our quadratic equation becomes,

according to question, we have said that if the population has twice its initial population, then it becomes

so, time taken to reach this above mentioned population is given by

now, we know that time can't be negative so, we take t=9.149 years.

hence, at 24 february, 2014 the population gets twice of its initial population.

answer; equivalent to a one(1) horsepower motor;