A ship is sailing towards the north at a speed of $1.25 m/s$  the current is taking it towards the east at rate of $1m/sec$ and a sailor is climbing a vertical pole on the ship at the rate of $0.5m/sec$. then the integer part of the velocity of the sailor in space is 

We take the unit vectors $\widehat{\mathrm{i}},\widehat{\mathrm{j}},$ and $\widehat{\mathrm{k}}$ parallel to the east ,north and vertically upwards in the direction of pole respectively. then the velocity vectors of the current, and the sailor are respectively, $\widehat{\mathrm{i}}$ ,1.25 $\widehat{\mathrm{j}}$and 0.5 $\widehat{\mathrm{k}}$. velocity $\overrightarrow{\mathrm{v}}$ of the sailor in space Is the resultant of these vectors  
hence,  $\overrightarrow{\mathrm{v}}=\widehat{\mathrm{i}}+1.25\widehat{\mathrm{j}}+0.5\widehat{\mathrm{k}}$
Then, $\left|\overrightarrow{\mathrm{v}}\right|=\sqrt{1+{(1.25)}^2+{(0.5)}^2}$
$=\sqrt{1+(1.5625+(0.25)}$
$=\sqrt{2.8125}=1.677\mathrm{m}/\sec$