9514 1404 393
Answer:
7.83 km/h
Step-by-step explanation:
At her constant pace, Nina's time for 6 km will be found by the proportion ...
(time for 6 km)/(6 km) = (time for 9 km)/(9 km)
time for 6 km = (6 km)/(9 km) × (75 min) = 50 min
Jo's time for the same distance will be 4 minutes less: 50 -4 = 46 min. Jo's speed is ...
speed = distance/time
= (6 km)/(46/60 h) = 360/46 h ≈ 7.83 km/h . . . . Jo's speed
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<em>Additional comment</em>
From the 6 km point, the remaining race is half the distance already run, so will take half the time already taken. As we know, Nina will finish in 25 more minutes; Jo will finish in 46/2 = 23 more minutes, 2 minutes ahead of Nina.
Answer:
8/-7
Step-by-step explanation:
using the equation: y₂-y₁/x₂-x₁
10-2/0-7 = 8/-7
Answer: 29 cans.
Step-by-step explanation:
20 can survive 24 days with 15 cans.
If X is the number of days that a man can survive with one can of rations.
so X is in the units can/day
then we have that:
24/15*X = 20
X = 20*15/24 = 12.5
This means that a man can live 12.5 days with a can of food.
then, for 16 men and 36 days we have:
(36/C)*12.5 = 16
C = (36/16)*12.5 = 28.1215
And we can not have a 0.1215 of a can, so we should round it up to 29 cans.
So x + y = 45, and 4x + 5y = 195. Get y by itself. Subtract x from both sides in the first equation to get y = 45 -x, and subtract 4x from the second equation to get 5y = 195 - 4x. Divide by 5 to both sides to get y = 39 - 4/5x. 39 - 4/5x = 45 - x. Add x to both sides to get 39 - 1/5x = 45. Subtract 39 from both sides to get -1/5x = 6. Divide by -1/5 to get x = -30, or 30. In the first equation, do 30 + y = 45. Subtract 30 from both sides to get y = 15. Check. 4(30) + 15(5) = 195, or 120 + 75 = 195.
Answer:
Mean height of 159
Step-by-step explanation:
Add 153 and 165, then divide by 2 to find the average of 159.
