Question

The size of a red blood cell is 0.000007 m and and that of a plant cell is 0.00001275 m . Show that a red blood cell is half of plant cell in size.​

Answer 1

We have :

size of a red blood cell = 0.000007 m = $\frac{7}{10 {}^{6} } m = (7 \times {10}^{ - 6})m$

size of a plant cell = zero 0.00001275 m = $\frac{1275}{ {10}^{8} }m \: = \: ( \frac{1.275 \times {10}^{3} }{ {10}^{8} })m$

= $\frac{1.275}{ {10}^{(8 - 3)} }m = \frac{1.275}{ {10}^{5} }m = (1.275 \times {10}^{ - 5}m$

$\frac{size \: of \: a \: red \: blood \: cell}{size \: of \: a \: plant \: cell} = \frac{7 \times {10}^{ - 6} }{1.275 \times {10}^{ - 5} }$

$= \frac{7 \times {10}^{( - 6 + 5)} }{1.275} = \frac{ 7\times 10 {}^{ - 1} }{1.275}$

$= \frac{7}{(1.275 \times 10)} = \frac{7}{12.75} = \frac{7}{13}(nearly)$

$= \frac{1}{2}(approximately)$

∴ size of a red blood cell =

$\frac{1}{2} \times (size \: of \: a \: plant \: cell).$