Logarithm
- If log 90 = 1.9542 then log 3 equals to ?
-
View Hint View Answer Discuss in Forum
Given log90 = 1.9542
⇒ log(32 x 10) = 1.9542
⇒ 2log 3 + log 10 = 1.9542Correct Option: C
Given log90 = 1.9542
⇒ log(32 x 10) = 1.9542
⇒ 2log 3 + log 10 = 1.9542
∴ log 3 = 0.9542 / 2 = 0.4771
- If 2log4x = 1 + log4 (x-1), find the value of x. ?
-
View Hint View Answer Discuss in Forum
∵ 2log4x = 1 + log4(x-1)
⇒ log4x2 = log44 + log4(x-1)
⇒ x2 = 4(x-1)Correct Option: A
∵ 2log4x = 1 + log4(x-1)
⇒ log4x2 = log44 + log4(x-1)
⇒ x2 = 4(x-1)
⇒ x2 - 4x + 4 = 0
⇒ (x-2)2 = 0
∴ x = 2
- If log 3 = 0.477 and (1000)x = 3, then x equals to ?
-
View Hint View Answer Discuss in Forum
∵ (1000)x = 3
⇒ xlog 103 = log 3Correct Option: A
∵ (1000)x = 3
⇒ xlog 103 = log 3
⇒ 3x = log 3
∴ x = log 3 / 3 = 0.477 / 3 = 0.159
- If 55-x = 2x-5, find the value of x . ?
-
View Hint View Answer Discuss in Forum
∵ 55-x = 2x-5
⇒ 55-x = 2-(5-x)
⇒ (5-x)log 5 = -(5-x)log 2
⇒ (5-x)log 5 + (5-x)log 2 = 0Correct Option: A
∵ 55-x = 2x-5
⇒ 55-x = 2-(5-x)
⇒ (5-x)log 5 = -(5-x)log 2
⇒ (5-x)log 5 + (5-x)log 2 = 0
⇒ (5-x){log 5 + log 2 } = 0
⇒ (5-x){log10/2 + log 2 } = 0
⇒ (5-x){log10 - log 2 + log 2} = 0
⇒ 5-x = 0
∴ x = 5
- If log8 x + log4 x + log2x =11, then the value of x is ?
-
View Hint View Answer Discuss in Forum
∵ log23 x1 +log22 x1 + log2x = 11
⇒ 1/3log2x + 1/2log2x + log2x = 11Correct Option: D
∵ log23 x1 +log22 x1 + log2x = 11
⇒ 1/3log2x + 1/2log2x + log2x = 11
⇒ (1/3 + 1/2 +1)log2x = 11
⇒ 11/6log2x = 11
⇒ log2x = 11 x 6 / 11 =6
∴ x = 26 = 64