Aboat travels upstream for 120 miles in 3 hours and returns in 2 hours traveling downstream in a local stream of water. what is the rate of the boat in still water and the rate of the current?

Let the rate of the current be x mph and rate of the boat in still water be y mph.

So the relative speed of the boat with the current ( downstream) = y + x and against the current (upstream) it = y - x.

Then , using speed = distance / time:-

y - x = 120/3 = 40

y + x = 120/2 = 60

Adding the 2 equations:-

2y = 100

y = 50

And substituting in the frst equation:-

50 - x = 40

x = 10

- Rate of boat in still water = 50 mph and rate of the current = 10 mph.

7! = 7×6×5×4×3×2

3! = 3× 2

as 7! is multiple of 3! because 7! contains 3! that is 3× 2 as factor

so 7! /(3! ) = 7× 6× 5× 4

= 42 × 20

= 840

its b) 840✌✌✌

dhruv⭐

(sin 42)/31. = sinx)/37

sinx = 37 (sin42)/31

= 37× 0.66/31 = 0.787

x= 51.9

other angle opposite to y = 180-51.9-42

= 180- 93.9 =86.1

so

sin42)/31 = sin 86.1)/y

0.021 = 0.997 /y

y= 0.997/0.021 =47.47