A girl was travelling in a boat, suddenly wind starts blowing and blows her hat and started floating back downstream. The boat continued to travel upstream for 12 more minutes before she realized that her hat had fallen off. She turned back downstream and she caught her hat as soon as she reached the starting point. If her hat flew off exactly 2 km from where she started. What is the speed of the water?

the speed of the boat; X

the speed of the current; Y

BC’s distance = boat upstream time*boat upstream speed; 12(X-Y)

CA’s distance = t(X+Y)

AB's distance = (12+t)Y

AB + BC = CA

(12+t)Y+12(X-Y)= t(X+Y)

t = 12

S = 2/24 min =

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Why CA = t(X+Y) ? why not (12+t)(X+Y)?

Why AB = (12+t)Y? why not just 12y?

How 24 min in last step?

the speed of the boat; X

the speed of the current; Y

BC’s distance = boat upstream time*boat upstream speed; 12(X-Y)

CA’s distance = t(X+Y)

AB's distance = (12+t)Y

AB + BC = CA

(12+t)Y+12(X-Y)= t(X+Y)

t = 12

S = 2/24 min =

**5 kmph**---------------------------------------

Why CA = t(X+Y) ? why not (12+t)(X+Y)?

Why AB = (12+t)Y? why not just 12y?

How 24 min in last step?

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