Question

Discs of radius 4 cm are cut from rectangular plastic sheet of length 84cm and width 24cm.how many complete discs can be cut out?

Answer 1

this will help you.ans is 40 sheets

Answer 2

$Given \: radius \:of \: a \:disc (r) = 4 \:cm$

$\underline { \blue { Dimensions \:a \: rectangle : }}$

$Length (l) = 84 \:cm , \\and \: breadth (b) = 24\:cm$

/* According to the problem given */

$Number \: of \: complete \: discs \: cut \:out \\from \: the \: rectangular \: sheet = n$

$\red{n} = \frac{ Area \:of \:the \: rectangular\:sheet }{Area \: of \:the \:circular \:disc}$

$\implies n = \frac{ l\times b}{\pi r^{2}} \\= \frac{ 84 \times 24}{\frac{22}{7} \times 4^{2}} \\= \frac{ 84 \times 24\times 7}{22\times 4\times 4}\\= \frac{441}{11} \\= 40.09$

Therefore.,

$\red { Number \: of \: discs \:can \:be }\\\red{ cut \:out } \green {= 40}$

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