Solving exponential equations Quiz

1. Solve $2^x=10$ to 3 significant figures.

• A. $0.301$
• B. $8$
• C. $3.32$
• D. $5$

2. Solve $7^{x+1}=50$ to 3 significant figures.

• A. $0.01$
• B. $1.01$
• C. $2.01$
• D. $6.14$

3. Solve $4\mathrm{e}^{3x}=20$, giving the exact answer.

• A. $x=\frac13\ln5$
• B. $x=\ln\frac{5}{3}$
• C. $x=\frac13\ln16$
• D. $x=\frac{\ln5}{4}$

4. A population grows by 8% each year. After how many whole years does it first exceed double its starting size?

• A. $8$
• B. $9$
• C. $13$
• D. $10$

5. Which is the correct solution of $3^x=12$?

• A. $x=\lg4$
• B. $x=\frac{\lg3}{\lg12}$
• C. $x=\frac{\lg12}{\lg3}$
• D. $x=4$