15/15 or 1 is your answer.
Answer:
The error is at step (3) .
The correct step (3) will be,

=
[by using the laws of indices]
All other steps are correct.
Step-by-step explanation:
The error is at the step (3) , because the student has tried to prove the quotient rule of logarithms by using the property i.e., 'The quotient rule of logarithm' itself , i.e. ,by assuming the property does hold before proving it. So, the proof is fallacious.
The correct step (3) will be,

=
[by using the laws of indices]
All other steps are correct.
Answer:
The 6 Lego kits can be selected from the 9 available Lego kits in 84 ways.
Step-by-step explanation:
Use combinations to solve this problem.
Combination is defined as the selection of <em>r</em> elements from <em>n</em> distinct objects irrespective of the order. The objects cannot be replaced.
There are 9 Lego kits available.
And the total number of children is 6.
That is, we need to select 6 Lego kits from the 9 available Lego kits.
6 Lego kits can be selected from the 9 available Lego kits in
ways.
Solving the combination as follows:

Thus, there are 84 ways to select 6 Lego kits from 9 available Lego kits.
B= number of beakers which there are 450
t= number of test tubes
the answer is 1.46