[問題]GWD11-36

由 **Shawn1983** » 2006-05-29 13:32

The age of the Earth is approximately 1.3 1017 seconds, and one year is approximately 3.2 107 seconds. Which of the following is closest to the age of the Earth in years?

A. 2.5*10^9
B. 4.1*10^9
C. 1.9*10^10
D. 2.5*10^11
E. 4.1*10^11
答案是B 看不懂題目說啥
請大家幫忙了~~~~

由 **scujean** » 2006-05-29 15:47

Shawn1983 \$m[1]:The age of the Earth is approximately 1.3 * 10^17 seconds, and one year is approximately 3.2 * 10^7 seconds. Which of the following is closest to the age of the Earth in years?

A. 2.5*10^9
B. 4.1*10^9
C. 1.9*10^10
D. 2.5*10^11
E. 4.1*10^11
答案是B 看不懂題目說啥
請大家幫忙了~~~~

你原本題目沒打清楚，算的我一頭霧水
地球的年紀用秒來表示=1.3 * 10^17
而一年等於= 3.2 10^7 seconds
算法：[1.3 * 10^17]/ [3.2 10^7 ]=0.41*[10^10]=4.1*[10^9]

由 **jeremy1983** » 2006-05-30 02:24

我覺得不太需要算出精確的0.41
因為在分數運算下先看成1.3無法除以3.2 所以要向10的次方項借一位

也就是說 10的次方數會遞減一位為10^16
然後分數的部分 13/3.2大概是4點多
這樣解題速度應該可以快一點 ^^"

[問題]GWD11-36

[問題]GWD11-36

Re: [問題]GWD11-36

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