Answer:
2.4 hours or 2 hours and 24 minutes
Step-by-step explanation:
Jack mows 1/6 of the lawn per hour while Marilyn mows 1/4 of the lawn together. Adding up those rates yields in their combined mowing rate:

The time required for them to mow the entire lawn is:

It would take them both 2.4 hours to mow the lawn together.
Black socks on monday - 3/9 or .33%.
white socks on tuesday - 5/9 or .55%
Explanation: Probability of black socks on Monday:
Total pair of socks: 1 + 3 + 5 = 9
Number of black socks on Monday: 3
3/9 = 1/3 (or divide to get a percentage)
Probability of white socks on Tuesday:
Total pair of socks: 9
Number of white socks on Tuesday: 5
5/9
The slope is the factor in front of x, so slope is 9.
The y intercept is 7 (that's the point of cross the y axis, where x=0)
There are multiple definitions of "standard form" for lines, so here are the two i can think of:
9x - y = -7 (the implicit function form)
or
y-7 = 9*(x-0) (the point-slope form)
Lmk if you have questions.
Answer:
- train: 40 kph
- plane: 140 kph
Step-by-step explanation:
Let t represent the speed of the train in km/h. Then 4t-20 is the speed of the plane. Travel times are the same, so we can use the formula ...
time = distance/speed
and equate the travel times.
110/t = 385/(4t-20)
Cross multiplying gives ...
110(4t -20) = 385t
440t -2200 = 385t . . . . . eliminate parentheses
55t -2200 = 0 . . . . . . . . . subtract 385t
t -40 = 0 . . . . . . . . . divide by 55
t = 40 . . . . . . . . . . . add 40; train's speed is 40 kph
4t -20 = 140 . . . . . . find plane's speed; 140 kph
The train's speed is 40 km/h; the plane's speed is 140 km/h.
_____
<em>Check</em>
Train's travel time = 110 km/(40 km/h) = 2.75 h.
Plane's travel time = 385 km/(140 km/h) = 2.75 h.