"Will is twice as old as Jill."
Jill's age . . . . . J
Will's age . . . . 2J .
"Three years ago . . .
Jill's age then . . . . . J - 3
Will's age then . . . . 2J - 3
". . . Jill's age then was 2/5 of Will's age then."
J - 3 = (2/5) (2J - 3)
Multiply
each side by 5 : 5J - 15 = 2 (2J - 3)
Divide
each side by 2 : 2.5 J - 7.5 = 2J - 3
Subtract 2J
from each side: 0.5 J - 7.5 = -3
Add 7.5
to each side: 0.5 J = 4.5
Multiply
each side by 2 : J = 9
Jill is 9 y.o. now.
Will is 18 y.o. now.
Answer:
1.5 hours
Step-by-step explanation:
Answer:
See below in bold.
Step-by-step explanation:
You work in fractions of the city streets done per hour:
1/200 + 1/400 = 1 /x where x is the number of hours taken by 2 teams.
Multiply through by the LCM 400x:
2x + x = 400
3x = 400
x = 133.33 hours.
As there are 168 hours in a week they will have enough time.
Answer:
Part A: 5
Part B: 2
Step-by-step explanation:
to find the mean all you have to do is add all the numbers together and then divide it by how many numbers there are in the data set
3+4+4+4+5+6+6+8=40
40÷8=5
so the mean is 5
next to find the mean of absolute deviations you need to subtract each number in the data set from the mean then divide it by how many numbers are in the data set (if you get a negative like 6-5=-1 just take away the negative sign to make it positive)
5-3=2
5-4=1
5-4=1
5-4=1
5-5=0
6-5=-1
6-5=-1
8-5=-3
2+1+1+1+0+1+1+3=10
10÷5=2
so the mean absolute deviation is 2
