If a sample initially contains 100 g of a radioactive isotope, how much will be left after 3 half lives? question 1 options: 50 g 25 g 12.5 g 6.25 g

In france, grapes are 1.95 euros per kilogram. what is the cost of grapes, in dollars per pound, if the exchange rate is 1.14 dollars/euro? (2.6)

Why is retrograde motion an apparent motion

Sum of brother and sisters age is 26. four times the brothers age is subtracted from three times the sisters age, the difference is 8. what are the ages of the brother and sister?