Let speed of the boat in still water = x miles per hour
Let speed of the current = y miles per hour
When water and current both flow in same direction then effective speed will be sum of both speeds that is (x+y)
now plug the given values in formula speed=distance/time
we get equation:
(x+y)=160/8
or x+y=20...(i)
When water and current both flow in opposite direction then effective speed will be difference of both speeds that is (x-y)
now plug the given values in formula speed=distance/time
we get equation:
(x-y)=160/40
or x-y=4
or x=4+y...(ii)
plug value of x into (i)
4+y+y=20
4+2y=20
2y=16
y=8
plug value of y into (ii)
x=4+8=12
Hence final answer is given by:
Speed of the boat in still water = 12 miles per hour
Speed of the current = 8 miles per hour
Answer: 1) 1/3,654 2) 3/406 3) 72,684,900,288,000 4) 120
<u>Step-by-step explanation:</u>
1) First and Second and Third
2) First and Second
The lengths of sides of a triangle have to satisfy the triangle inequality, which states that the sum of the two shorter sides must exceed the length of the third side.
Here 9+8=17 (not greater), so these segments do not form a triangle.
165 is answer we also use a formula
5 ( n/2(2a + ( n-1)d)
in that n=6 ,a=3 , d= 1
