Answer:
x=40 and y= 60
Step-by-step explanation:
<u>step:1</u>
Let 'x' and 'y' are two numbers
given data the sum of two numbers is 100
x+y = 100......(1)
Given difference of two numbers are
x - y = -20 ......(2)
<u>Step :2</u>
solving the equation (1) and (2)
adding the equations (1) and (2)
x+y+x-y=100-20
cancelling 'y' terms are
2 x = 80
dividing "2" on both sides, we get
x = 40
<u>Step :3</u>
substitute x = 40 in equation (1)
x + y =100
40 + y = 100
subtracting "40" on both sides, we get
40 + y - 40 = 100 -40
y = 60
Final answer:-
The two numbers are x = 40 and y= 60
Only 20%of earths water is useable
Answer:
D.) The expected value is 1.78
Step-by-step explanation:
The expected value of a probability distribution is evaluated using the formula.
Expected Value,
Therefore, from the given probability distribution, we have:
E(X)=(0*0.3)+(1*0.2)+(2*0.16)+(3*0.2)+(4*0.04)+(5*0.1)
E(X)=1.78
The Expected value of X is 1.78.
The correct option is D.