If the box of $\displaystyle 5$ granola bars was $\displaystyle \$2.50$, this means that each granola bar cost $\displaystyle \$0.50$ because $\displaystyle \$2.50$ divided by $\displaystyle 5$ is $\displaystyle \$0.50$. 

If Mindy then sold each granola bar for $\displaystyle \$1.00$, the profit per bar would be $\displaystyle \$1.00$ minus the $\displaystyle \$0.50$ cost of the bar, which is equal to $\displaystyle \$0.50$. 

If she sold all $\displaystyle 5$ granola bars, then she would have made a profit of $\displaystyle \$0.50\cdot5$, which is $\displaystyle \$2.50$.

Given that each pair of earrings requires $\displaystyle 4$ beads, the number of beads that $\displaystyle 30$ pairs of earrings would require is equal to:

$\displaystyle 4\cdot30=120$

Since Maria has $\displaystyle 120$ beads, she has a sufficient number of beads to make $\displaystyle 30$ earrings. The other jewelry arrangements will result in there being a shortage of beads: Maria would need $\displaystyle 400$ beads to make $\displaystyle 20$ necklaces ($\displaystyle 20\cdot20=400$), $\displaystyle 130$ beads to make $\displaystyle 13$ bracelets ($\displaystyle 13\cdot10=130$), and $\displaystyle 122$ beads to make $\displaystyle 11$ bracelets and $\displaystyle 3$ pairs of earrings ($\displaystyle (11*10)+(3*4)=110+12=122$).

If the cost of being part of a tennis club for two people is $\displaystyle \$20$ a month, that means the annual cost for two people will be $\displaystyle 12\cdot\$20=\$240$. 

If two people share this cost, that means that each person will have to pay $\displaystyle \$120$ because half of $\displaystyle \$240$ is $\displaystyle \$120$. 

Therefore, the correct answer is $\displaystyle \$120$.

If Lisa sends an average of $\displaystyle 12$ emails a day and sends emails over a course of $\displaystyle 7$ days, that means that the total number of emails that she sends will be equal to $\displaystyle 12\cdot7=84$. Therefore, the correct answer is $\displaystyle 84$.

If a song is $\displaystyle 2$ minutes and $\displaystyle 15$ seconds long, this is the equivalent of being $\displaystyle 135$ seconds long. ($\displaystyle 2$ minutes is equal to $\displaystyle 120$ seconds and $\displaystyle 120+15=135$.)

$\displaystyle \frac{1}{5}$ of $\displaystyle 135$ is $\displaystyle 27$ because $\displaystyle \frac{1}{5}\cdot \frac{135}{1}=\frac{135}{5}=27$. Therefore, $\displaystyle \frac{3}{5}$ of $\displaystyle 135$ is equal to $\displaystyle 3*27=81$. Therefore, $\displaystyle 81$ seconds (or $\displaystyle 1$ minute and $\displaystyle 21$ seconds) will go by before the drum solo begins. 

If Anita buys twenty sweaters for $\displaystyle \$15.00$ each and sells them for $\displaystyle \$25.00$ each, this means that she makes $\displaystyle \$10.00$ profit per sweater. If she sells $\displaystyle 20$ sweaters, the profit that she makes will be $\displaystyle 20\cdot\$10.00$, which is equal to $\displaystyle \$200.00$. 

Find the product of two numbers by multiplying them together. $\displaystyle 12 \times 5 = 60$, so the correct answer is $\displaystyle 60$.

When multiplying one negative factor with one positive factor the product will always be negative. 

Thus, the solution is:

$\displaystyle -9\times27=-243$

When multiplying two negative factors the product will always be positive. 

Thus, the solution is:

$\displaystyle -6\times-36=216$

When multiplying one negative factor with one positive factor the product will always be negative. 

Thus, the solution is:

$\displaystyle -25\times15=-375$