Simultaneous equations, any method

Weekly wages at a certain factory are normally distributed with a mean of $400 and a standard deviation of $50. find the probability that a worker selected at random makes between $450 and $500

The function f(x) = 14,600(1.1)* represents the population of a town x years after it was established. what was the original population of the town?

15m is what percent of 60m; 3m; 30m; 1.5 km? the last one is km not m