Aperson has 20 coins, all nickels and dimes, worth one dollar and 40 cents. how many nickels are there? if n = number of nickels and d = number of dimes, which system of equations represents the problem? n + d = 20 and n + d = 1.40n + d = 20 and 5n + 10d = 1.40n + d = 20 and 5n + 10d = 140

Mercury poisoning is dangerous overload of mercury within the body. a major source of mercury within the body, a major source of mercury poisoning is consuming fish that contain mercury. certain fish are more prone to having higher levels of mercury than others. the pie chart shows the distribution of four breeds of fish at a hatchery. the hatchery has approximately 6,000 fish. a biologist from the centers for disease control and prevention randomly test 5% of each breed of fish for mercury content. her findings are shown in the following table. based on the biologist's findings, if a single salmon is randomly selected from those that were tested, what is the probability that this particular fish would have a dangerous mercury level? a) 0.001 b) 0.004 c) 0.02 d) 0.08

What is 32+4 x (16 x 1/2) -2 show your work}

Can someone me with the property questions for 12 13 and 14 plz