Question 1180301: In a game at an amusement park, a player can win 20 points, 25 points, or 30 points.
The probability of winning these points is given below.
Points and Probability
20--->0.6
25--->x
30--->y
If Jenny expects to win 22.5 points by playing the game once, the value of x is
? and the value of y is ?
Answer by ikleyn(52918)   (Show Source):
You can put this solution on YOUR website! .
In a game at an amusement park, a player can win 20 points, 25 points, or 30 points.
The probability of winning these points is given below.
Points and Probability
20--->0.6
25--->x
30--->y
If Jenny expects to win 22.5 points by playing the game once, the value of x is
? and the value of y is ?
~~~~~~~~~~~~~~~~~
From the condition, we have these two equations for unknowns x and y
x + y = 1 - 0.6
0.6*20 + 25x + 30*y = 22.5,
or, in other form
x + y = 0.4
25x + 30y = 10.5
Solve it by any way you want.
ANSWER. x = 0.3; y = 0.1.
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