Answer:
1 hour after they leave
Step-by-step explanation:
The distance each travels is proportional to its speed. The given speeds are at right angles to each other in a 5:12 ratio. The Pythagorean theorem tells you the hypotenuse of such a right triangle will have length ...
√(5²+12²)=√169 = 13
That is the speeds are in the ratio 5:12:13, where 13 represents the relative separation speed. Actual speeds are then 50 mph : 120 mph : 130 mph.
So the distance between the boat and steamer will be increasing at 130 mph. The distance will be 130 miles after 1 hour.
Answer:
3.5
Step-by-step explanation:
Why not look up "standard deviation" yourself, to be sure? But yes, the std. dev. is the sqrt of the variance.
Answer:10 hours to read all 250 pages
Step-by-step explanation:
The given numbers are 13, 27, 81, 21,43, 48,23,39,45.
Square number is that number which is a perfect square means if you multiply a number by itself the number you obtained is a perfect square i.e it's square root is a natural number.
√13=not a natural number
√27=√3×√3×√3=3√3=irrational number
√81=√9×√9=9=a natural number
√21=not a natural number
√43=not a natural number
√48=4√3=not a natural number
√23=not a natural number
√39=not a natural number
√45=3√5=not a natural number
So, out of following numbers 13 27 81 21 43 48 23 39 45→81 is the only square number.
