I need help to understand and solve this problme by writing formula ( equation)

(Without using excel) plzzz

""Today your cousin is celebrating his 35th birthday and he want to start saving money in order to get an income during his retirement. he made the following decisions:

* to put today a deposit of 10,000 dollars in his savings account.

* to make an annually payement of $ 3000 in his savings account on each anniversary starting from 36th birthday until 60th birthday. your cousin wants to have a monthly pension during 20 years of his retirement from his 60th birthday.

The money earn an annual rate 8% compounded per quarterly.

 question 1 

how much will have accumulated at his 60th birthday After his last deposit?

 question 2 

how much monthly pension will he receive at the end of each month?

 Question 3 

.what will be the monthly annuity amount he will receive at the end of each month if your cousin would like to have an amount of 20,000 dollars in a savings account at the end of the 20 years of his retirement?

 Question 4 

.how much per year should your cousin have been depositing from the 36th to the 60th birthday so that he could receive an annuity of $ 25,00 at the end of each month and have an amount of 50,000 in his savings account at the end of his retirement? knowing that he will always make a deposit of $ 10,000 on the day he opens his savings account.

Question 5 

now you will use the following interest rates:

• annual rate 10% compounded per quarterly fir the first 10 years.
• annual rate 12% compounded half-yearly for the 15 following year.
• Annual rate 8% per year for the last 20 years .

find the monthly pension that your cousin will receive at the end of each month during the retirement period if he still intends to deposit the amount of $ 10,000 in his savings account today and make a deposit of $ 3,000 per year from the 36th to 60th anniversary.