Government limits for sea water are based on an iodine 131 value of 40 Bq/L and a cesium 137 value of 90 Bq/L. On April 17, 2011, sea water contamination levels based on samples 20 km from the site had iodine 131 and cesium 137 concentrations of 161 Bq/L and 186 Bq/L, respectively. How much time must pass before the sea water sample reaches the government's limits?

Two fire-lookout stations are 190 miles apart, with station a directly south of station b. both stations spot a fire. the bearing of the fire from station a is upper n 55 degrees upper e and the bearing of the fire from station b is upper s 60 degrees e. how far, to the nearest tenth of a mile, is the fire from each lookout station?

Graph red beads cost $1 an ounce and gold beads cost $3 an ounce. juanita wants to purchase a 12-ounce mixture of red and gold beads that she can sell for $2 an ounce. the solution of the system shows the number of beads needed for juanita to break even. x + y = 12, x + 3y = 24 how many ounces of red beads will juanita buy to break even? how many ounces of gold beads will she buy?

Gabrielle's age is two times mikhail's age. the sum of their ages is 84. what is mikhail's age?