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Find out the results of the following operations. (i) 117.3 xx 0.0024 "" (ii) 9.27 div 41 (iii) 42 xx 0.041 "" (iv) 124.2 + 52.487 (v) 124.2 - 52.487 "" (vi) sqrt(58.97) (vii) (17.5)^(2). |
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Answer» Solution :(i) 0.0024 has 2 SIGNIFICANT FIGURES. Hence 117 .3 is rounded off to have `2 + 1 = 3` significant figures . It becomes 117 only. Now `117 xx 0.0024 = 0.2808` This is to be rounded off to have two significantfigures only. The result is 0.28. (ii) 41 has only 2 significant digits. Hence 9.27 can have 2 + 1 = 3 significant digits. It has 3 significant digits only. No need for rounding off. `(9.27)/( 41) = 0.2260975` This is to be rounded off to two significant digits. The result is 0.23. (iii) Both number have two significant digits. `42 xx 0.041 = 1.722`. This is to be rounded off to 2 significant digits. The result is 1.7. (iv) As this is a SUM, we have to consider decimal places. 124.2 has only one decimal place. Hence 52.487 is to be rounded off to `1+1 =2` decimal places. It becomes as 52.487 = 52.49 Now 124.2 + 52.49 = 176.69. This is to be rounded off to one decimal place. The result is as 176.69 = 176.7. (v) Here again, we have `124.2 ""52.487 = 124.52.49 = 71.71` This is to be rounded off to one decimal place The result is 71. 7. (vi) `sqrt(58.97) = 7.679` This has GOT the same number of significant digits (4) as 58.97. (vii) `(17.5)^(2) = 306.25`. The original number 17.5 has only 3 significant digits. And hence the result will be 306 (Here we have to consider the significant figures) . |
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