The average of three numbers is 45. two of the numbers are equal. the last number is 89. what are the two missing numbers?

Mathematics

2 answers:

san4es73 [151]3 years ago

5 0

Answer:23

Step-by-step explanation:

Let a, b and c be the three numbers

a + b + c / 3 = 45

a = b (given)

So 2a + c / 3 = 45

c = 89 (given)

So 2a + 89 /3 = 45

2a + 89 = 135

2a = 46

a= 23

Since a= b, b = 23

So the numbers are 23 and 23

trasher [3.6K]3 years ago

4 0

The average of a set of data is equal to the sum of the values divided by the number of data present. So, if we have three numbers, the average would be:

let x, y and z represent the three numbers
average = x + y + z / 3 = 45

Two number are equal in value, so let x = y. Substituting the value to the expression of average,

45 = x + x + z / 3
45 = 2x + z / 3

It said that the last number is 89 so z is equal to 89.

45 = 2x + 89 / 3
135 = 2x + 89
46 = 2x
x = 23

Therefore, the two numbers are both 23.

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Aliun [14]

Answer: The answer is 9.

Step-by-step explanation: Given that five members of gymnastics team and 7 members of weight lifting team are travelling in two vans to the rival school for competition. We are to find the number of ways in which they can ride in two vans such that no van contains more than eight passengers and there is at least one member of each team in each van.

Let 'g' and 'w' denote a member of gymnastics team and weight lifting team respectively.

Then, the possibilities are

For 1 g, we can choose 3w, 4w, 5w, 6w.

For 2g, we can choose 2w, 3w, 4w, 5w, 6w.

For 3g, we can choose 1w, 2w, 3w, 4w, 5w.

For 4g, we can choose, 1w, 2w, 3w, 4w.

Therefore, there are (4 + 5 + 5 + 4) = 18 ways.

Since, here the position of the vans does not matter, so the options are double here. Hence, we must divide it by 2.

Thus, the total number of ways = 9.

4 0

3 years ago

tia_tia [17]

Answer:

$8-6i$

Step-by-step explanation:

Multiply out $(3-i)^2$ in order to find out which expression it is equivalent to.

1) Since the whole quantity is squared, write it out as $(3-i)(3-i)$ .

$(3-i)^2\\(3-i)(3-i)$

2) Multiply binomials by using the FOIL method. Multiply the terms that are listed first in each binomial, then the ones that are listed outermost when looking at both binomials, then innermost, and finally the last terms listed in each binomial. Simplify and combine like terms.

$(3-i)(3-i)\\9 - 3i - 3i + i^2$