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Answer:
Step-by-step explanation:
The value of n should be equal to -27.
Answer:
The number of children are 4 out of which 3 are girls
Step-by-step explanation:
Data provided in the question:
P(Two randomly selected children are girls) =
now,
let the number of children be 'n'
the number of girls be 'x'
thus,
P(Two randomly selected children are girls) = =
also,
=
thus,
=
or
=
or
2x(x-1) = n(n-1)
now
for x = 3 and n = 4
i.e
2(3)(3-1) = 4(4-1)
12 = 12
hence, the relation is justified
therefore,
The number of children are 4 out of which 3 are girls
4x -3y + z = -10...............(1)
2x +y + 3z = 0...............(2)
-x +2y - 5z = 17...............(3)
First we multiply 3*(2) and add it to (1)
6x +3y +9z =0..................+(1)..................> 10x + 10z = -10......(4)
Then we multiply -2*(2) and add it to (3)
-4x -2y -6z =0 ...................+(3)................> -5x -11z = 17...........(5)
Multiply 2*(5) and add it to (4)
-10x -22z = 34...................+(4).................> -12 z = 24 ..............>>> z = -2
Substitute z in (4)............> 10x +10(-2) = -10.............................>>> x = 1
Substitute x and z in (2).....> 2(1) +y + 3(-2) = 0..................>>> y = 4
Solution (x,y,z) = (1,4,-2)