Exponential equations solved with logarithms, and continuous compounding
Grade 11 Math Worksheet - Building Confidence
Circle the best answer, or write your answer on the line.
Jun solves 3^x = 20 on the class board by writing x = log 20 ÷ log 3. To the nearest hundredth, what is x?
Kira solves 2^x = 50 on the class board by writing x = log 50 ÷ log 2. To the nearest hundredth, what is x?
Luz solves 4^x = 30 on the class board by writing x = log 30 ÷ log 4. To the nearest hundredth, what is x?
Milo solves 2 · 5^x = 40 in a math book. Which choice gives x as a logarithm?
- x = log₅ 20
- x = log₂₀ 5
- x = log₅ 40
- x = log 40
Noah solves 3 · 2^x = 21 in a math book. Which choice gives x as a logarithm?
- x = log₇ 2
- x = log₆ 21
- x = log₂ 21
- x = log₂ 7
Pia solves 4 · 3^x = 44 in a math book. Which choice gives x as a logarithm?
- x = log₁₂ 44
- x = log₃ 11
- x = log₃ 44
- x = log₁₁ 3
Read this first
Use this
Growth table, × 1.06 on each yearly arrow: row 0: $1; row 1: $1.06; row 2: $1.1236; the rows go on until $2.
Ms. Ortiz's savings fund earns 6% a year, compounded yearly, and Ren solves 1.06^t = 2. To the nearest tenth of a year, how long until the money doubles?
Use this
Growth table, × 1.07 on each yearly arrow: row 0: $1; row 1: $1.07; row 2: $1.1449; the rows go on until $2.
Mr. Dunn's savings fund earns 7% a year, compounded yearly, and Zee solves 1.07^t = 2. To the nearest tenth of a year, how long until the money doubles?
Use this
Growth table, × 1.04 on each yearly arrow: row 0: $1; row 1: $1.04; row 2: $1.0816; the rows go on until $2.
Ms. Hale's savings fund earns 4% a year, compounded yearly, and Bo solves 1.04^t = 2. To the nearest tenth of a year, how long until the money doubles?
Ms. Hale's savings fund pays 4% a year, compounded continuously. Using A = Pe^(rt), how much does Luz find $2,500 grows to in 6 years?
