Lodine-131 has a half-life of 8 days. If authorities found an original sample of 2.5 grams right after an emission from the plant how much iodine-131 would be left 30 days later?

The annual snowfall in a town has a mean of 38 inches and a standard deviation of 10 inches. last year there were 63 inches of snow. find the number of standard deviations from the mean that is, rounded to two decimal places. 0.44 standard deviations below the mean 2.50 standard deviations below the mean 0.44 standard deviations above the mean 2.50 standard deviations above the mean

Which property was used to simplify the expression? 3c+9 +4c=3c+4c+9

What number gives you a irrational number when added to 2/5