Answer:
There are 60 girls and 40 boys in the class.
Step-by-step explanation:
Given that the mean weight of 100 students in a certain class is 71kg, while the mean weight of boys is 65kg and that of girls is 75kg, to determine what is the number of boys and girls the following calculation must be performed:
1 x 75 + 0 x 65 + 75
0.9 x 75 + 0.1 x 65 = 74
0.8 x 75 + 0.2 x 65 = 73
0.7 x 75 + 0.3 x 65 = 72
0.6 x 75 + 0.4 x 65 = 71
Thus, there are 60 girls and 40 boys in the class.
Answer:
3x-4
Step-by-step explanation:
Answer:
26.4 km/hr
Step-by-step explanation:
Sofia and Diego drive to work.
For Sofia
We convert miles to km
Sofia drives 72 miles in 1.5 hours.
1 mile = 1.6 km
72 miles = x
x = 72 × 1.6 km
x = 115.2 km
We find the speed in km/hr
Speed = Distance /Time
= 115.2km/1.5 hours
= 76.8 km/hr
For Diego
Diego drives 126 km in 2 hour 30 min.
Speed = Distance/Time
Time = 2 hour 30 min = 2.5 hours
Speed = 126km/2.5 hours
= 50.4 km/hr
The difference between their average speeds in km/h is calculated as:
76.8 km/hr - 50.4 km/hr
= 26.4 km/hr
Answer:
no
Step-by-step explanation:
pls give brainliest :)
Answer:
0.02
infinete 0.0222222222
Step-by-step explanation:
or 45
