please show me the steps so i can understand it

Expenditures for maintenance of a certain machine are expected to be $900 in year two, $1,400 in year five, and a uniform amount of $2,000 in years six through nine. At an interest rate of 10% per year, the present worth of the expenditures is nearest to:

A) $4,521

B) $4,973

C) $5,192

D) $5,549

Costs for maintenance of buildings at an industrial complex are expected to be $1,000 in year three, $1,200 in year four and amounts increasing by $200 per year thereafter through year nine. At an interest rate of 10% per year, the present worth of the expenditures is nearest to:

A) $5,163

B) $5,575

C) $6,133

D) $7,421

The costs of fuel for a smelting operation are expected to be $50,000 in year three, $52,500 in year four and amounts increasing by 5% per year thereafter through year ten. At an interest rate of 8% per year, the present worth of the fuel cost is nearest to:

A) $190,400

B) $204,600

C) $277,900

D) $336,300

Payments of $1,000 in year two and $4,000 in year five are equivalent to uniform payments in years three through seven at an interest rate of 10% per year nearest to:

A) $899

B) $985

C) $1,177

D) $3,732

At an interest rate of 10% per year, the length of time required from time zero to recover an initial investment of $10,000 by receipts of $1,000 per year beginning in year three is nearest to:

A) 10 years

B) 20 years

C) 100 years

D) never

The number of years from now that an initial investment of $1,000,000 would be recovered from uniform receipts of $131,000 per year beginning three years from now at an interest rate of 10% per year is nearest to:

A) 24

B) 29

C) 35

D) 40