Answer:
16 : 28
Step-by-step explanation:
If 12 out of the 28 pupils are female, we can calculate the number of males by subtracting the number of females from the total number of pupils.
28 - 12 = 16
So, there are 16 males in the class. Now, we know that the ratio of males : total is 16 : 28.
I hope this helps! Have a lovely day!! :)
(brainliest is much appreciated!!)
<span>Which shows the elements of the set of whole number multiples of four less than 21?
The multiples of 4 are 4, 8, 12, 16, 20, 24, 28,...
Then, the set of the multiples of four less than 21 is {4, 8, 12, 16, 20}
A: {1, 2, 3, 4, 5}
B: {4, 8, 12, 16, 20}
C: all real numbers
D: null set
Which shows the set(s) the number 2.77 is an element of?
2.77 is a real number, it is not a natural number, and it is not a whole number.
A: real numbers
B: real numbers and natural numbers
C: natural numbers and whole numbers
D: null set
Given sets:
D = {5, 6, 7, 8, 9, 10}, E = {1, 3, 5, 7, 9, 11}, F = {3, 6, 9, 12}
What is D n E?
I believe the question is what is D ∩ E, which is the elements that are as much in D as in E. This is {5,7,9}
A: {1, 3, 5, 6, 7, 8, 9, 10, 11}
B: {5, 7, 9}
C: {9}
D: null set</span>
Answer: they would be able to talk to each other for 1.5 hours
Step-by-step explanation:
If each brother has a communication device that allows him to talk to the other for up to a 210-mile range, by the time they are 210 miles apart, they won't be able to communicate to each other. This means that they would have travelled a total distance of 210 miles.
Let t represent the time it takes either brothers to travel his own distance.
the first brother driving at 55 miles per hour. If the first brother has a one-hour head start, this means that the time spent by the first brother is (t + 1) hour.
Distance = speed × time
Distance travelled by the first brother is
55(t + 1) = 55t + 55
The second brother was driving at 55 miles per hour. This means that distance travelled by the second brother in t hours is
50t
Since the total distance covered is 210 miles, then
55t + 55 + 50t = 210
105t = 210 - 55 = 155
t = 155/105 = 1.476 hours
Approximately 1.5 hours
