C-03-Q170mediumsingle_mcq

Boatman covers $x$ km against current in $t_1$ hr, with current in $t_2$ hr. Speed of boat = ?

a $\dfrac{x}{2}\left(\dfrac{1}{t_1} + \dfrac{1}{t_2}\right)$
b $\dfrac{x}{2}\left(\dfrac{1}{t_2} - \dfrac{1}{t_1}\right)$
c $\dfrac{x}{2}\left(\dfrac{1}{t_1} - \dfrac{1}{t_2}\right)$
d $\dfrac{x(t_1+t_2)}{2}$

ব্যাখ্যা

Upstream speed is $\dfrac{x}{t_1}=b-c$ and downstream $\dfrac{x}{t_2}=b+c$ ; adding and halving gives boat speed $b = \dfrac{x}{2}\left(\dfrac{1}{t_1}+\dfrac{1}{t_2}\right)$ . The current cancels when the two speeds are averaged.

এই অধ্যায়ের আরও প্রশ্ন

Algebraic Expressions — সব প্রশ্ন দেখুন (219টি) →

Boatman covers $x$ km against current in $t_1$ hr, with current in $t_2$ hr. Speed of boat = ?

\dfrac{x}{2}\left(\dfrac{1}{t_1} + \dfrac{1}{t_2}\right)

\dfrac{x}{2}\left(\dfrac{1}{t_2} - \dfrac{1}{t_1}\right)

\dfrac{x}{2}\left(\dfrac{1}{t_1} - \dfrac{1}{t_2}\right)

\dfrac{x(t_1+t_2)}{2}

Boatman covers xxx km against current in t1t_1t1​ hr, with current in t2t_2t2​ hr. Speed of boat = ?

ব্যাখ্যা

এই অধ্যায়ের আরও প্রশ্ন

Boatman covers xxx km against current in t1t_1t1​ hr, with current in t2t_2t2​ hr. Speed of boat = ?

ব্যাখ্যা

এই অধ্যায়ের আরও প্রশ্ন

Boatman covers $x$ km against current in $t_1$ hr, with current in $t_2$ hr. Speed of boat = ?

Boatman covers $x$ km against current in $t_1$ hr, with current in $t_2$ hr. Speed of boat = ?