Answer:
4%
Step-by-step explanation:
The probability that two smoke is the product of the probabilities that each smokes, provided the students are selected independently.
... 0.20 × 0.20 = 0.0400 = 4%
6.2 x 10^10
a^2b^2+6abx+9c^2
(a + b)2 = a2 + 2ab + b2
(ab+3c)^2=(ab)^2+2ab*3c+(3c)^2