Answer:
1 time unit
Step-by-step explanation:
There is a 1 in 3 chance that the time until the bulb burns out is zero, and a 2 in 3 chance that the time is the average between 0 and 3 (since it is uniformly distributed). Therefore, the expected value for the time until it burns is:

The expected value of the time until the lightbulb burns out is 1 time unit.
Decrease = Rs 800- Rs 640= Rs 160
Percentage decrease = (Decreased amount / Original amount) * 100
= 640/ 800 * 100 = 80%
Answer:
C. 3 : 5
D. 24 : 40
Step-by-step explanation:
Select two ratios equivalent to 6 : 10
Checking all options
A. 20 : 12
20 / 12
= 10 /6
= 10 : 6
B. 32 : 50
= 32 / 50
= 16 / 25
C. 3 : 5
3 / 5
= 6 / 10
3/5 is equivalent to 6 / 10
D. 24 : 40
24 / 40 = 12 / 20
= 6 / 10
= 6 : 10
Options C and D are correct
The answer is A because a sample of 500 boys and girls from middle schools across the state represents the population.
Answer:
The no. of possible handshakes takes place are 45.
Step-by-step explanation:
Given : There are 10 people in the party .
To Find: Assuming all 10 people at the party each shake hands with every other person (but not themselves, obviously) exactly once, how many handshakes take place?
Solution:
We are given that there are 10 people in the party
No. of people involved in one handshake = 2
To find the no. of possible handshakes between 10 people we will use combination over here
Formula : 
n = 10
r= 2
Substitute the values in the formula





No. of possible handshakes are 45
Hence The no. of possible handshakes takes place are 45.