Proofs how do you solve them

A dress that normally cost $89.50 is on sale for 45% off. What is the sale price of the dress?

If the diameter of a student's brain is about 6 inches, and you assume its shape is approximately a hemisphere, then what is the volume of the student's brain? A) 188.4i n³ B) 251.2 in³ C) 452.16 in³ D) 904.32 in³

If a shark is swimming 25mph and a boat is going 105mph who would make it to the island first?

In a lottery, 5000 tickets are sold for $1 each, one first prize of $2000, 1 second prize of $500, 3 third prizes of $100, and 10 consolation prizes of $25 are to be awarded. What are the expected net earnings of a person who buys one ticket?

What is the volume of an aquarium that is 2 yards wide, 1.5 yards deep, and 1 1/3 yard long?

Write an algebraic to model the phrase. the base price of a car plus 7.5% tax represents the total cost of the car.

Ursula has 1/2 cup of butter. She uses 1/4 cup of butter to make a batch of brownies. How many batches of brownies can Ursula make with 1/2 cup of butter?

When this polynomial is simplified, what is the coefficient of x: 10x^2+8x-6x^3+4x^2+12x^3-x+20 ... ?

A club is making posters to raise money. the printer charges a base fee of $270 and $2 per poster for supplies. a person sells each poster for $5. how many posters must he sell to make profit of $300?

Write ratio in simplest form 6:3/5