Question

at a particular time, the length of the shadow of qutub minar whose height is 72 meter is 80 meter. what is the height of an electric pole whose shadow at the same time is of the length 1000cm​

Answer 1

S O L U T I O N :-

• 1000 cm=10 m

Let's use variation :-

Table :

$\boxed{\begin{array}{c|c|c} \sf x & 72 & 10 \\ \sf y & 80 & ?\end{array}}$

• Here 'x' varies inversly :

${:}\longrightarrow \sf x\propto {\dfrac {1}{y}}$

${:}\longrightarrow \sf x_1y_2=x_2y_1$

${:}\longrightarrow \sf 72\times 10=80 \times y_2$

${:}\longrightarrow \sf y_2={\dfrac {72\times {\cancel {10}}}{{\cancel{80}}}}$

${:}\longrightarrow \sf y_2={\dfrac {72}{8}}$

${:}\longrightarrow \sf y_2=9\:m$

${:}\longrightarrow \underline {\boxed{ \bf y_2=900\:cm}}$

$\huge{\therefore}$ Height of pole is 900 cm.