Can someone help me with these 3 questions I don’t know how to do it

Afurniture store has 1,500 chairs in storage. a manager uses three delivery receipts to simulate samples to check 100 chairs and note the number of brown chairs. suppose the actual number of brown chairs is 1,080. about how many brown chairs are

Circle a has a diameter of 7 inches, a circumference of 21.98 inches, and an area of 38.465 square inches. the diameter of circle b is 6 inches, the circumference is 18.84 inches, and the area is 28.26 square inches. part a: using the formula for circumference, solve for the value of pi for each circle. (4 points) part b: use the formula for area and solve for the value of pi for each circle. (4 points)

An arithmetic series a consists of consecutive integers that are multiples of 4 what is the sum of the first 9 terms of this sequence if the first term is 0