Answer:
Speed of river's current = 5 mph
Step-by-step explanation:
Let 'd' be the distance covered
Let x be the speed of the rivers current
Speed upstream = 15-x
speed downstream = 15+x
Time = distance / speed
time upstream = 
time downstream = 
the ferry trip upstream takes twice as long as its return trip downstream
= 
divide both sides by d
= 
cross multiply
Add 2x on both sideds
subtract 15 from both sides and divide by 3
x=5
Speed of river's current = 5 mph
25 meters is the same as 250 decimeters tall.. hope this helped
3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679821480865132823066470938 etc.
If it is just an estimate then it would be around <em>4</em>. 15.1 is pretty close to 16 which has a perfect square root of 4. Since it is a square both length and width would be the same. To check it you can just square 4 or 4 times 4 and get 16. Hopefully I helped! And sorry if I am wrong.
BTW the exact answer would be 3.88~ (square root of 15.1) just incase you needed that. :)
If 5/6 of them are sleeping then 40 alligators are awake
