$13.30<br>× 80<br><br>How I solve This

seven out of every 8 students surveyed owns a bike. The difference between the number of students who own a bike and those who d

guajiro [1.7K]

So if x people were surveyed, $\frac{7}{8}$ people owned a bike and $\frac{1}{8}$ did not.

The difference between them is 72:
$\frac{7}{8}$ x-\frac{1}{8} [/tex] =72
so this means that
$\frac{6}{8}$ x=72

let's simplify:

$\frac{3}{4}$ x=72

and divide by 3:

$\frac{1}{4}$ x=24

and mupliply by 4:

x=96

so 96 people were surveyed

5 0

3 years ago

Plastic parts produced by an injection-molding operation are checked for conformance to specifications. Each tool contains 15 ca

Rainbow [258]

Answer:

(A) 0.006593 or 0.6593%

(B) 0.01538 or 1.538%

Step-by-step explanation:

The total number of possibilities to pick 3 parts out of 15 possible parts is given by the following combination:

$n=\frac{15!}{(15-3)!3!}=\frac{15*14*13}{3*2*1}\\n=455\ ways\\$

(A) There are only three possibilities for which the inspector finds exactly one nonconforming part (NCC, CNC, CCN). Therefore, the probability is:

$P(N=1) = \frac{3}{455}=0.006593 =0.6593\%$

(B) There are three possibilities for which the inspector finds exactly one nonconforming part, three possibilities for two nonconforming parts (NNC, CNN, NCN), and one possibility for all nonconforming parts (NNN). The probability that the inspector finds at least one nonconforming part is:

$P(N>0) =P(N=1)+P(N=2)+P(N=3) \\P(N>0) = \frac{3}{455}+ \frac{3}{455}+ \frac{1}{455}\\P(N>0) =0.01538 =1.538\%$