Hi, could someone please give me explanation and guide me steps to do these questions? Thank you very much!

13) Kiddie Company makes jungle gyms and tree houses for children. For jungle gyms, the price is $120 and variable expenses are $90 per unit. For tree houses, the price is $200 and variable expenses are $100. Total fixed expenses are $880,000. Last year, Kiddie sold 1,600 gyms and 400 tree houses. How many jungle gyms need to be sold at break-even?

a) 1,600

b) 4,000

c) 16,500

d) 16,000

14) Using the information from Question 13. How many tree houses need to be sold at break-even?

a) 400

b) 4,000

c) 40,000

d) 16,000

15) The following information pertains to Wilson Company for the year:

Estimated overhead $320,000

Estimated machine hours 40,000

Actual overhead $337,500

Actual machine hours 45,000

Using machine hours as the basis, calculate the pre-determined overhead rate.

a) $8/machine hour

b) $7.50/machine hour

c) $7.11/machine hour

d)$8.44/machine hour

16) Using the information from Question 15. What is the total applied overhead?

a) $360,000

b) $300,000

c) $284,400

b) $379,800

17)Using the information from Question 15. What is the overhead variance?

a) $37,500 under-applied

b) $22,500 over-applied

c) $22,500 under-applied

d) $17,500 under-applied