Answer:
<h3>By 161700 ways this test batch can be chosen.</h3>
Step-by-step explanation:
We are given that total number of bulbs are = 100.
Number of bulbs are tested = 3.
Please note, when order it not important, we apply combination.
Choosing 3 bulbs out of 100 don't need any specific order.
Therefore, applying combination formula for choosing 3 bulbs out of 100 bulbs.
 read as r out of n.
 read as r out of n.
Plugging n=100 and r=3 in above formula, we get

Expanding 100! upto 97!, we get
=
Crossing out common 97! from top and bottom, we get 
=
Expanding 3!, we get 
=
= 100 × 33  × 49
= 161700 ways.
<h3>Therefore,  by 161700 ways this test batch can be chosen.</h3>