Answer:21
Step-by-step explanation: plug in 19 and 1
1x3 is 3 plus 19 is 21
Answer
Find out the how long did they rest in 8 hours.
To prove
As given
contestants in a dance-a-thon rest for the same amount of time every hour.
A couple rests for 25 minutes in 5 hours .
As
25 mintues = 5 hours

1 hours = 5 mintues
Thus in 1hours a the dance -a-thon rest for 5 mintues.
Now for 8 hours.
8 hours = 8 × 5 mintues
= 40 mintues
Therefore in 8 hours a dance-a-thon rest for 40 mintues.
78 minutes...............................................
Answer: 0.205
Step-by-step explanation:
The probability in one flip is equal to 0.5.
Now, if we do 10 flips, we want 4 times that the coin ends in heads and the other 6 times it must end in tails, so the probability is:
0.5^4*0.5^6 = 0.5^10
Now, this is the case where in the first 4 flips we get heads and in the other 6 we get tails, but we have other ways to get only 4 heads (for example in the last 4 flips, 2 at the beginning and 2 at the end, etc)
So we also need to calculate all the possible permutations of 4 heads in 10 flips. this is:
C = 10!/(10 - 4)!*4! = (10*9*8*7)/(4*3*2*1) = 210
So the probability that we are looking for is:
P = (0.5^10)*210 = 0.205
Answer:
Yes
Step-by-step explanation: No do you work