Step: 1
Any non zero digit, or any zero which serves a purpose other than to locate the decimal point is a significant digit.
Step: 2
(1.6 × 10 2 ) (1.2 × 10 - 5)
Step: 3
= (1.6 × 1.2)(10
2 × 10
- 5)
[Rearrange factors.]
Step: 4
= 1.92 × 10
- 3 [When two exponents having the same base are multiplied, their powers are added.]
Step: 5
The given two numbers have 2 significant digits.
Step: 6
≈ 1.9 × 10
- 3 [Approximate to 2 significant digits.]
Correct Answer is : 1.9 × 10 -3