Angela's average for six math tests is 87. on her first four tests she had scores of 93, 87,82, and 86. on her last test, she scored four points lower than she did on her fifth test. what scores did angela receive on her fifth and sixth tests? a. fifth test=90; sixth test = 86 b. fifth test =89; sixth test= 85 c. fifth test =85; sixth test = 81 d. fifth test= 85; sixth test= 89

The decibel level of sound is 50 db greater on a busy street than in a quiet room where the intensity of sound is watt/m2. the level of sound in the quiet room is db, and the intensity of sound in the busy street is watt/m2. use the formula , where is the sound level in decibels, i is the intensity of sound, and is the smallest sound intensity that can be heard by the human ear (roughly equal to watts/m2).

Suppose that sahil knows that 45 people with ages of 18 to 29 voted. without using a calculator, he quickly says then 135 people with ages of 30to 49 voted. is he correct? how might sohil have come up with his answer so quickly?

Aremote-controlled boat can travel at 4 feet per second in calm water. the boat traveled 48 feet with the current, and then it traveled 16 feet against the current in the same amount of time. how fast is the current?