The high school choirs participating in a fundraising sales contest. The choir will receive a bonus if they make 20 sales in the first week and improve their sales by three and every subsequent week. What is the minimum number of sales so choir could make in the first 12 weeks to qualify for the bonus?

A total of 53 sales to qualify for bonus

Step-by-step explanation:

In the first week, they required a sale of 20 tickets to recieve a bonus.

In subsequent weeks, they require a sale of (n + 3)

Where n = number of sale the previous week

Week 2, they'll require n + 3 = (20 + 3) sales = 23 sales

Week 3 = 23 + 3 = 26 sales

Week 4 = 26 + 3 = 29 sales

Week 5 = 29 + 3 = 32 sales

Week 6 = 32 + 3 = 35 sales

Week 7 = 35 + 3 = 38 sales

Week 8 = 38 + 3 = 41 sales

Week 9 = 41 + 3 = 44 sales

Week 10 = 44 + 3 = 47 sales

Week 11 = 47 + 3 = 50 sales

Week 12 = 50 + 3 = 53 sales

At the end of week 12, they require a total of 53 sale to qualify for bonus