BITSAT2017MathematicsBasics of MathematicsActual
If a = log 2 3 , b = log 2 5 and c = log 7 2 , then log 140 63 in terms of a , b , c is
Options
- A2 a c + 1 2 c + a b c + 1
- B2 a c + 1 2 a + c + a
- C2 a c + 1 2 c + a b + a
- DNone of these
Correct answer
D. None of these
Step-by-step solution
We have, log 140 63 = log 2 2 × 5 × 7 ( 3 × 3 × 7 ) = log 2 ( 3 × 3 × 7 ) log 2 2 2 × 5 × 7 = log 2 3 + log 2 3 + log 2 7 2 log 2 2 + log 2 5 + log 2 7 = 2 a + 1 c 2 + b + 1 c = 2 a c + 1 2 c + b c + 1