Plutonium–238 has a yearly decay constant of 7.9 × 10-3. if an original sample has a mass of 15 grams, how long will it take to decay to 12 grams? (at = a0e-kt) a. 3 years b. 12.3 years c. 28.3 years d. 139.1 years

What fraction of one year is 8 months

For the rule of 78, for a 12-month period, the last term in the sequence is 12 and the series sums to 78. for an 10 month period, the last term is and the series sum is . for a 15 month period, the last term is and the series sum is . for a 20 month period, the last term is and the series sum is

Somone me i want to know what 18 hours out of 24 hours in a fraction