Answer:
A.
Step-by-step explanation:
d = rt
If t is the time taken by the train, then the truck takes t+2 hours.
For the truck:
d = 45(t + 2)
For the train:
d = 60t
Total distance travelled by both:
= 2d
= 60t + 45(t + 2)
= 60t + 45t + 90
= 105t + 90 where t is the time taken by the train.
<span>What is the value of x?
2/3
4/3
(4)
6</span>
Answer:
2.0/4.0
Step-by-step explanation:
Answer:
she flipped the 2 and the 4
Step-by-step explanation:
if you flip the 2 and the 4 its 4/2 which is equal to 2
Answer:
Step-by-step explanation:
Given that a school has 20 classes: 16 with 25 students in each, three with 100 students in each, and one with 300 students for a total of 1000 students.
a) Y = no of students in the class out of 20 selected at random
Y can take values as
Y 25 100 300 Total
freq 16 3 1 20
P(Y) 16/20 3/20 1/20 1
y*p 20 15 15 50
E(Y) = 50
b) X = size of student from which one student is taken at random
X 25 100 300 Total
No of classes 16 3 1 20
Total students
(X*no of classes) 400 300 300 1000
P(x) 0.4 0.3 0.3 1
X*P 160 90 90 240
E(x) =240
c) On an average, a student at this school is in a class with 240 students. On average, a class at this school has 50 students.
i.e. expectation of number of students in a class is 50 while expectation of a student having students in the class is 240