During elementary school, Krystal received a weekly allowance of $8 for completing all of her chores. Now that she is in middle school and has more responsibility she is earning $12 a week. What is Krystal’s percent increase in her allowance? HELP ME

Brent works part-time at a clothing store. he earns an hourly wage of $15. if he needs to earn more than $45 in a day and works for x hours a day, which inequality represents this situation? a. 15x > 45 b. 15x < 60 c. x > 60 d. 15x < 45 e. x < 60

Adepartment store purchases screen-printed t-shirts at a cost of $5 per shirt. they mark up the price 150% (making the selling price 250% of the store's purchase price) and put them on the sales floor. every month that a t-shirt doesn't sell, the store reduces the selling price by 25%.

If the speed of an electromagnetic wave is 100,000 cm/s and its wavelength is 100 cm, what is its frequency? a) 100,000 cycles per second (hz) b) 1 × 10-3 cycles per second (hz) c) 10,000,000 cycles per second (hz) d) 1,000 cycles per second (hz)