I am having trouble with the following problems. Can someone please help me with these problems. I really need some help. I would really appreciate it. Thanks

1) During a recent period a real estate development company using the installment method of revenue recognition used a 40% gross profit percentage. The cost of land sold was $90,000. The selling price of land must have been?

2) If a company had $400,000 of retail land sales and a 40% gross profit percentage, what was the cost of the land sold?

3) A corporation sold a tract of land for $400,000 that had originally cost $240,000. The buyer will make three annual payments of: $130,000; $120,000; and $150,000.
a) The amount of gross profit recognized in the second year under the installment method is?
b) The amount of gross profit recognized in the second year under the cost recovery method is?

4) Carlson Business Machines Co. sold a computer to a customer for $600,000. The machine cost $390,000 and the installment contract calls for annual payments of $140,000 for five years. The excess amount of the payments over the sales price represents interest, which is to be spread evenly over the contract period.
a) Carlson's gross profit percentage on this contract is ?
b) The gross profit, under the installment method, recognized in year two of
The contract would be?

5) Gerardi Corporation sold a machine to Carney Co. for $700,000. The machine cost Gerardi $490,000. The contract calls for annual payments of $152,000; $500,000; and $252,000. Each payment includes an equal amount of interest. Gerardi uses the cost recovery method.
a) Gerardi's cost recovery in the first year of the contract would be?
b) Gerardi's gross profit in year two would be?
c) Gerardi's gross profit in year three would be?

6) Martin Construction Co. agreed to build a bridge for the town of Lemon Grove. The contract specifies that construction will take three years and Martin will receive $3,000,000. The company expects annual costs to be $1,350,000; $675,000; and $225,000.
a) Assume Martin uses the completed contract method. Expenses recognized in year three will be?
b) Assume Martin uses the percentage of completion method. Gross profit for year two will be?
c) Assume Martin uses the percentage of completion method. Revenue recognized in year three will be?

7) Nodzak Construction agreed to build a warehouse for $10,000,000 over the next three years. Estimated cost for years one through three are: $3,150,000; $2,250,000; and $3,600,000
a) Gross profit for year one, assuming the percentage of completion method
Would be?
b) Revenue recognized in year two assuming the percentage of completion
Method would be?
c) Gross profit recognized in year three assuming the completed contract
Method would be?

Once again I would appreciate all the help

I got the following answers to the questions. Please let me know if I am anywhere close to the answer or if I am way off. Thanks once again.

1) $150,000
2) $240,000
3)a) $48,000
b) $10,000
4)a) 35%
b) $42,000
5)a) $84,000
b) $26,000
c) $184,000
6)a) $2,250,000
b) $225,000
c) $300,000
7)a) $350,000
b) $2,500,000
c) $1,000,000