HELPPPPPP pls give explaiantikn or work pls pls pls pls brainliest

Mathematics

1 answer:

Andru [333]3 years ago

3 0

Answer:

Elizabeth had 30 stamps originally.

Step-by-step explanation:

Let,

x be the number of stamps Elizabeth have.

Number of stamps given to John = 1/6 of x = $\frac{1}{6}x$

Remaining stamps = $x-\frac{1}{6}x = \frac{6x-1x}{6} = \frac{5}{6}x$

Stamps given to Peter = 1/5 of remainder = $\frac{1}{5}*\frac{5}{6}x = \frac{1}{6}x$

Number of stamps left = 20

Now,

$\frac{1}{6}x + \frac{1}{6}x + 20 = x\\\\\frac{1x+1x+120}{6} = x\\\\\frac{2x+120}{6} = x\\\\2x + 120 = 6x \\\\120 = 6x - 2x \\\\120 = 4x \\4x = 120$

Dividing both sides by 4

$\frac{4x}{4}=\frac{120}{4}\\x=30$

Hence,

Elizabeth had 30 stamps originally.

You might be interested in

A study of long-distance phone calls made from General Electric Corporate Headquarters in Fairfield, Connecticut, revealed the l

lesya692 [45]

Answer:

The probability that a call last between 4.2 and 4.9 minutes is 0.4599

Step-by-step explanation:

Let X be the length in minutes of a random phone call. X is a normal distribution with mean λ=4.2 and standard deviation σ=0.4. We want to know P(4.2 < X < 4.9). In order to make computations, we will use W, the standarization of X, given by the following formula

$W = \frac{X-\mu}{\sigma} = \frac{X-4.2}{0.4}$

We will use $\phi$ , the cummulative distribution function of W. The values of $\phi$ are well known and the can be found in the attached file

$P(4.2 < X < 4.9) = P(\frac{4.2-4.2}{0.4} < \frac{X-4.2}{0.4} < \frac{4.9-4.2}{0.4}) = P(0 < W < 1.75) = \\ \phi(1.75) - \phi(0) = 0.9599-0.5 = 0.4599$