Julian practiced the clarinet for a total of 2 hours and 15 minute on Wednesday and Friday.He practiced twice as long on Friday as he did on Wednesday.How many minutes did he pr…

Question

asked Jan 2, 2020 165k views

1 Answer

Adamscott · Answer 1 · 2020-01-06T15:20:43+0000

Answer: He practiced 90 minutes on Friday.

Explanation:

Let be "w" the amount of minutes Julian practiced the clarinet on Wednesday and "f" the amount of minutes Julian practiced the clarinet on Friday.

Convert the total time he praticed on Wednesday and Friday to minutes. Since
1h=60min , 2 hours and 15 minutes is:

60min+60min+15min=135min

Set up a System of equations:

$\left \{ {{w+f=135} \atop {f=2w}} \right.$

Applying the Substitution Method, you can subsitute the second equation into the first equation and solve for "w":

$w+(2w)=135\\\\w=(135)/(3)\\\\w=45$

Finally, substitute this value into the second equation to find "f":

$f=2(45)\\\\f=90$

Therefore, he practiced 90 minutes on Friday.