If , , and , then is equal…

MATHEMATICS · Single correct · A Level · Mathematics · Exponentials and logarithms · Exponentials and logarithms

Problem

a=\log_{24}12

b=\log_{48}36

, and

c=\log_{36}24

, then

1+abc

is equal to (1)

2ab

(2)

2bc

(3)

2ca

(4)

ab+bc