# maths

a man was trying to swim to a buoy placed at a distance of 200m out in the sea. it took him 1 min to swim 20m. then a wave pushed him back 10m and he rested for about 1min before swimming again. he continued in his way for the rest of their journey. how long would it take the man to swim to the buoy?

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1. i think it will take 40 min

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2. Make a stepped graph.
*At the end of 1 min he is at 20 m
at the beginning of 2 min he is at 10 ,
at the end of 2 min he is at 10 m , (he rested 1 min)
*at the end of 3 min he is at 30 m
at the beginning of 4 min he is at 20m
at the end of 4 min he is at 20 m
* at the end of 5 m he is at 40 m

look at the lines with a *
..
we have (1,20) , (3,30) , (5,40)
slope = 10/2 = 5
distance = 5(minute) + b , using (1,20)
20 = 5(1) + b
15 = b

distance = 5(minute) + 15 , where minute is an integer

200 = 5m+15
5m = 185
m = 37
He will reach the 200 m mark at the end of the 37th minute.

We will assume that as soon as he reaches the 200 m mark, he will grab and hold on before the wave pushes him back.

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