whats log 20 given that log 2 = 0.3010 & log 3 = 0.4771 without using a calculator?

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whats log 20 given that log 2 = 0.3010 & log 3 = 0.4771 without using a calculator?

may someone please explain step by step. im a newbie and im lost....

thanks

2007-11-29 22:35:58 · 3 answers · asked by * blobbaah- 1 in Science & Mathematics ➔ Mathematics

3 answers

Here's one of the properties of logarithms:

log a + log b = logab

You actually don't need log 3.

log 20 = log (2*10)
log20 = log2 + log10

Since log 10 = 1

Then log 20 = 1 + 0.3010
log 20 = 1.3010

2007-11-29 22:50:29 · answer #1 · answered by Anonymous · 0⤊ 0⤋

20=2*10 so log 20 = log 2 +log10 = 1.3010
no need of log 3

2007-11-30 06:42:51 · answer #2 · answered by santmann2002 7 · 1⤊ 0⤋

20= 2*10= log20= log2+ log10.
0.3010 + 1.0= 1.3010.
Ans, log20= 1.3010.

2007-11-30 07:42:18 · answer #3 · answered by Sasi Kumar 4 · 0⤊ 0⤋