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3 years ago

7

The swimming team has competed 45 races this season. They have won 30 races so far. How many races will the team need to win tod

ay for the team to have a 75% success rate?

1 answer:

julia-pushkina [17]3 years ago

7 0

Answer:

The team needs to win 15 races today.

Step-by-step explanation:

The team has completed 45 races so far and has won 30 so far.

The current success rate is

$r = \frac{30}{45} * 100\% = 66.7\%$

We need this success rate to be 75%

Then the team must win a number x of races such that

$r = \frac{30 + x}{45 + x} = 0.75$

Now we solve the equation for x.

$\frac{30 + x}{45 + x} = 0.75\\\\30 + x=0.75(45 +x)\\\\30 + x=0.75(45) +0.75x\\\\x- 0.75x = 33.75-30\\\\0.25x = 3.75\\\\x= \frac{3.75}{0.25}\\\\x=15$

Finally the team need to win 15 carreras today

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