Choose the equation that is equivalent to this statement: 4 is 80% of x

Which speed is the fastest (use 1 mile ≈ 1.6 kilometers)? a. 12 miles/hour b. 18 feet/second c. 19 kilometers/hour d. cannot be determined

Tessa bought stock in a restaurant for $253.00. her stock is now worth $333.96. what is the percentage increase of the value of tessa's stock? a.) 81% b.) 32% c.) 24% d.) 76%

Ibeg you to me 20. a reaction produces 4.93 l of oxygen, but was supposed to produce 1 mol of oxygen. what is the percent yield?