Question

In a stack there are 5 books each of thickness 20mm and 5 paper sheets each of thickness 0.016mm . what is the total thickness of the stack .​

Answer 1

$\rm{Total \: number \: of \: books \: in \: the \: stack \: = \sf \purple{5}}$

$\rm{thickness = \sf \purple{20mm}}$

$\rm{Total \: thickness \: of \: the \: books = \sf \purple{20×5=100}}$

$\rm{Total \: number \: of \: paper =\sf \purple{5}}$

$\rm{thickness \: of \: the \: paper =\sf \purple{0.016mm}}$

$\rm\footnotesize{Total \: thickness \: of \: the \: paper \: \sf \purple{=5×0.016=0.080}}$

$\rm \blue{Total \: thickness \: of \: the \: stack = }$

$\fcolorbox{purple}{pink}{=100+0.080=100.080=1.0008×10² mm}$

Answer 2

Thickness of a book = 20mm

Thickness of 5 books =5\times20\ mm5×20 mm

= 100mm

Thickness of 1 paper sheet = 0.016 mm

Thickness of 5 paper = 0.016\times50.016×5

= 0.080 mm

total thickness of stack = Thickness of 5 books + thickness of 5 paper sheets

= 100+0.080

= 100.08

$1.0008 \times {10}^{2}$