GMAT Math Practice Test #1

Answer B: The logarithm of a product is equal to the sum of the logarithms of the individual number. The logarithm of a number, the number being same as the base is 1. log3 (9X27X81) = log3 9 + log3 27 + log3 81 = 2 log3 3+ 3 log3 3 +4 log3 3 = 2 + 3 + 4 = 9

Key takeaway: While learning logarithm pay more attention to the basic rules of logarithm and develop an understanding of the range of the values of logs.