Answer:
there are 9 quarters and 19 dimes
Step-by-step explanation:
Let x be the number of dimes and y the number of quarters
-dimes: 0.1x
-quarters: 0.25y
-the total amount of coins : x + y = 28
=> x = 28 - y
We have the equation:
0.25y + 0.1x = 4.15
0.25y + 0.1(28 - y) = 4.15
0.25y + 2.8 - 0.1y = 4.15
0.15y = 1.35
y = 9
x = 28 - y
= 28 - 9
= 19
X represent the number of laps Marcy swam, 114x represent the number of times Toni swam.
20 + 0.80(114x) + 15 + 0.85x = 257
20 + 91.2x + 15 + 0.85x = 257
92.05x + 35 = 257
Required equation is 92.05x + 35 = 257
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Answer:
Probability that exactly 5 of them have blue eyes is 0.1165.
Step-by-step explanation:
We are given that Researchers claim that 8% of people have blue eyes. Suppose the researchers' claim is true. Mrs. Greene has a Geometry class with 40 students.
The above situation can be represented through Binomial distribution;

where, n = number of trials (samples) taken = 40 students
r = number of success = exactly 5
p = probability of success which in our question is % of people
having blue eyes, i.e; 8%
<em>LET X = Number of students having blue eyes</em>
So, it means X ~ 
Now, Probability that exactly 5 of them have blue eyes is given by = P(X = 5)
P(X = 5) = 
= 
= 0.1165
Therefore, Probability that exactly 5 of them have blue eyes is 0.1165.