Can anyone help me ASAP

Write a corresponding real world problem to represent 2x - 125=400

You have 6 dollars +12 pennies +to quarters + 4 dimes=2 nickels how much do you have

For which of the following counts would a binomial probability model not be reasonable? a)the number of people in a classroom born in januaryb) the number of people in a classroom with red hair c) the number of people admitted to a hospital in a day with a particular disease d) the number of heart beats in a one-minute perio.