Exponential Word Problems Math 12
1. For a biology experiment, the number of cells present is 1000. After 4 hours the count is estimated to
be 256 000. What is the doubling period of the cells?
2. Pascal joined an investment club and was guaranteed 11.5% compounded annually. The minimum
period of time was five years.
a) Calculate the amount of money received at the end of 5 years if $1500 was invested in the
club?
b) How much interest did Pascal actually receive for investing the money?
3. Health officials found traces in radium-F beneath the local library. After 70 days they observed that a
certain amount of the substance decayed to 14 of its original mass. Determine the half-life of radium-F.
4. Radium is used in the making of luminous paint for watch dials. Raphael lost her watch in a
construction site. If it were found 8100 years later, what fraction of the original luminosity would be
left in the watch dial if the half life of radium is 1620 years?
1
5. How long will it take for a 1 gram sample of polonium-210 to lose all but 128
th of its radioactivity if its
half life is 140 days?
6. A bone found at an archaeological site was determined to be 19 000 years old. If the
amount of C14 in the bone was 0.47 grams, calculate the original amount of C14 in the bone.
7. In a recent dig, a human skeleton was unearthed. It was later found that the amount of Carbon-14 in it
had decayed to 1/16 of its original amount. If Carbon-14 has a half life of 5760 years, how old was the
skeleton?
Exponential Word Problems Math 12
1. For a biology experiment, the number of cells present is 1000. After 4 hours the count is estimated to
be 256 000. What is the doubling period of the cells?
2. Pascal joined an investment club and was guaranteed 11.5% compounded annually. The minimum
period of time was five years.
a) Calculate the amount of money received at the end of 5 years if $1500 was invested in the
club?
b) How much interest did Pascal actually receive for investing the money?
3. Health officials found traces in radium-F beneath the local library. After 70 days they observed that a
certain amount of the substance decayed to 14 of its original mass. Determine the half-life of radium-F.
4. Radium is used in the making of luminous paint for watch dials. Raphael lost her watch in a
construction site. If it were found 8100 years later, what fraction of the original luminosity would be
left in the watch dial if the half life of radium is 1620 years?
1
th of its radioactivity if its
5. How long will it take for a 1 gram sample of polonium-210 to lose all but 128
half life is 140 days?
6. A bone found at an archaeological site was determined to be 19 000 years old. If the
amount of C14 in the bone was 0.47 grams, calculate the original amount of C14 in the bone.
7. In a recent dig, a human skeleton was unearthed. It was later found that the amount of Carbon-14 in it
had decayed to 1/16 of its original amount. If Carbon-14 has a half life of 5760 years, how old was the
skeleton?
Exponential Word Problems Math 12
1. For a biology experiment, the number of cells present is 1000. After 4 hours the count is estimated to
be 256 000. What is the doubling period of the cells?
2. Pascal joined an investment club and was guaranteed 11.5% compounded annually. The minimum
period of time was five years.
a) Calculate the amount of money received at the end of 5 years if $1500 was invested in the
club?
b) How much interest did Pascal actually receive for investing the money?
3. Health officials found traces in radium-F beneath the local library. After 70 days they observed that a
certain amount of the substance decayed to 14 of its original mass. Determine the half-life of radium-F.
4. Radium is used in the making of luminous paint for watch dials. Raphael lost her watch in a
construction site. If it were found 8100 years later, what fraction of the original luminosity would be
left in the watch dial if the half life of radium is 1620 years?
1
th of its radioactivity if its
5. How long will it take for a 1 gram sample of polonium-210 to lose all but 128
half life is 140 days?
6. A bone found at an archaeological site was determined to be 19 000 years old. If the
amount of C14 in the bone was 0.47 grams, calculate the original amount of C14 in the bone.
7. In a recent dig, a human skeleton was unearthed. It was later found that the amount of Carbon-14 in it
had decayed to 1/16 of its original amount. If Carbon-14 has a half life of 5760 years, how old was the
skeleton?
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