John worked in a furniture store for a salary of $850 a month, plus a commission of 6% on sales over $20,000. How much did he earn in a month where he sold $36,000 worth of furniture?v

He earned in this month $1810

Step-by-step explanation:

∵ John worked in a furniture store for a salary of $850 a month

∴ His fixed salary = $850

∵ He takes a commission of 6% on sales over $20,000

∴ His commission = 6% on sales over $20,000

→ Change it to decimal by divide it by 100

∴ His commission = = 0.06 on sales over $2000

∵ In one month he sold $36,000 worth of furniture

∴ He will take a commission on the value that over $20,000

∵ The amount of selling over $20,000 = 36,000 - 20,000

∴ The amount of selling over $20,000 = $16,000

→ Multiply it by 0.06 to find his commission

∵ His commission = 0.06 × 16,000

∴ His commission = $960

→ Now let us find his total earn

∵ His total earn = his salary + his commission

∴ His total earn = 850 + 960 = 1810

∴ He earned in this month $1810

Consider for a moment building a tree with all possible choices. The first row would contain 8 books (each possible choice for the first book). Then, the second row would contain 7 books for each book in the first row (the choices possible for the second book). Otherwise, it would be 8*7. Following this principal, we continue to multiply down to 1. 8*7*6*5*4*3*2*1. This is also known as 8!, a factorial.
Finally, 8! = 40,320