Respuesta :
27 Hours
Explanation
Step 1
you can easily solve this by using a rule of three,
a) find the proportion
if
jack completed 68 math problems in 4 hours
[tex]\text{proportion}=\frac{68\text{ math problems}}{4\text{ hours}}=17\frac{problems}{\text{hour}}[/tex]Now, we have the proportion "the speed" of Jack.
Step 2
Let
x represents the time to finish 459 problems, the proportion is the same, so
[tex]\begin{gathered} 17\frac{problems}{\text{hour}}=\frac{459\text{ problems}}{x} \\ 17=\frac{459}{x} \end{gathered}[/tex]Step 3
finally, solve for x
[tex]\begin{gathered} 17=\frac{459}{x} \\ \text{Multiply both sides by x} \\ 17x=x\cdot\frac{459}{x} \\ 17x=459 \\ \text{Divide boths dies by 17} \\ \frac{17x}{17}=\frac{459}{17} \\ x\text{=}27 \end{gathered}[/tex]so, the answer is 27 hours
