When calculating probability you need to remember that probability is:
something that you are observing divided by total number of participants.
The number you get is relative value(has value between 0 and 1) and if you want to get it in percentage (more clearly) just multiply it with 100.
In this case we are observing blood type B persons. Number of them is 165.
Total number of persons is 1500. Therefore our calculation looks like this:
165/1500 = 0.11 or the probability is 0.11*100=11%
Answer:
40 km on the highway
30 km on the city roads
Step-by-step explanation:
Let x = highway
Let y = city road
The time formula: time = distance / speed.
1) Since we do not know the distance travelled on the highway and city roads but we do know the total time taken, we can say x + y = 70. Set the distances x and y and all equated to 2 hours, since we do not know them, nor do we know the time. This is called a system of equations.
x + y = 70
x/80 + y/20 = 2
2) Solve the system of equations using substitution.
x = 70 - y
---------------
70 - y/80 + y/20 = 2
70 + 3y/80 = 2
y = 30
---------------------------------
x + 30 = 70
x = 70 - 30
x = 40
Therefore, the delivery truck travelled 40 km on the highway and 30 km on the city roads.
-8 + 4 = 2u
-4/2 = 2u/2
-2 = u