It takes a boat going upstream 11 hours to cover the same distance, as it would cover in 9 hours going downstream. What is the speed of the boat if the speed of the current is 2 km/hr? PLEASE HELP ASAP. 100 points!!!

20 km/hr

Step-by-step explanation:

time taken by the boat going upstream = 11 hours

time taken for downstream movement = 9 hours

speed of the current = 2 km/h

distance traveled by the boat = d

Assume the speed of boat be x

we know,

distance =  speed × time

moving upstream

distance = speed × time

            d  = (x -2) × 11

downstream

             d = (x+2) × 9

now  

       (x+2) × 9 = (x -2) × 11

              2 x = 40

                 x = 20 km/hr

hence, the speed of the boat will be 20 km/hr

option a, c,d are correct.

step-by-step explanation:

from the given figure, it is given that z is equidistant from the sides of the triangle rst, then from triangle tzb and triangle szb, we have

tz=sz(given)

bz=zb(common)

therefore, by rhs rule,δtzb ≅δszb

by cpctc, sz≅tz

also, from δctz and δasz,

tz=sz(given)

∠tcz=∠saz(90°)

by rhs rule, δctz ≅ δasz, therefore by cpctc, ∠ctz≅∠asz

also,from δasz and δzsb,

zs=sz(common)

∠zbs=∠saz=90°

by rhs rule, δasz ≅δzsb, therefore, by cpctc, ∠asz≅∠zsb

hence, option a, c,d are correct.