A chemist needs a 30% iron alloy. How many grams of a 70% iron alloy must be mixed with 16 grams of a 20% iron alloy to obtain the requiered 30% alloy?

Thief steals an atm card and must randomly guess the correct threethree?-digit pin code from a 99?-key keypad. repetition of digits is allowed. what is the probability of a correct guess on the first? try?

What is the value of 5^4/5^6

What is the value of x in the equation 7x + 2 y = 48, when y = 3? COF x = 6 x = 7 x = 8 x = 9

Each side of the square below is 20 centimeters. The area of the circle inside the square is about 314 square centimeters. a. 43/200 b. 43/157 c. 157/200 d. 200/157

Which is the prime factorization of 114

A chef knows that ground beef used for hamburger is safe to eat once it reaches 160 degrees Fahrenheit. For optimized taste and safety, he will not allow a hamburger cooked to a temperature under 160 degrees or over 170 degrees to be served.

Find the unit rate 322 miles on 14 gallons of gas

Factor the expression x^{2} + 4x-21

Consider two boxes, one containing one black and one white marble, the other, two black and one white marble. a box is selected at random and a marble is drawn at random from the selected box. what is the probability that the marble is black? 37.

If runners in a long distance race were to run straight from the starting line to the finish line they would run 13 kilometers. However, the road they run makes them travel longer than that.