You and a friend have a hula hoop competition. you win 3 out of every 7 trials. your friend wins 5 more trials than you. how many trials are in the competition?

Respuesta :

Answer:

Total number of trials is 35.

Step-by-step explanation:

Given : Me and my friend have a hula hoop competition. I win 3 out of every 7 trials. My friend wins 5 more trials than me.  

To find : How many trials are in the competition?

Solution :

Probability of my winning is 3 out of 7 trials [tex]=\frac{3}{7}[/tex]

and probability of my friend's winning is  [tex]=1-\frac{3}{7}=\frac{4}{7}[/tex]  

Let there be n numbers of trials.

Therefore, my score after n trials [tex]=\frac{3n}{7}[/tex]

and my friend's score after n trials   [tex]=\frac{4n}{7}[/tex]

Now, the number of trials my friend won more than me is

[tex]\frac{4n}{7}-\frac{3n}{7}=\frac{n}{7}[/tex]

We know, that my friend won 5 more trials than me so comparing the actual and given we get,

[tex]\frac{n}{7}=5\\n=7\times5=35[/tex]

Therefore, total number of trials is 35.

We can also verify our answer by placing value of n,

After 35 trials I will win [tex]\frac{3\times 35}{7}=15[/tex] trials

and my friend will win [tex]\frac{4\times 35}{7}=20[/tex]  trials.

Hence, my friend won 5 more trials than me.