Taking a test doesn't lessen your risk of a heart attack
Answer:
0.0098
Step-by-step explanation:
Probability of being pregnant:100/1000
=1/10.
98% chance:=98/100 ×1/10
=98/1000
Therefore the probability that she really is pregnant is: 0.098
Answer:
3^4
Step-by-step explanation:
Simplifying an expression with expression with exponents:
If they are dividing, we keep the base and subtract the exponents. For example:

In this question:
5x - 3y = -11 (×2)
2x - 6y = -14 (x5)
10x - 6y = -22
10x - 30y = -70
---------------------- -
24y = 48
y = 2
1) in one minute for first wiil be 1/20
the other 1/30, it means that A paint in one minute 1/20 and B 1/30 then A+B in one minute 1/20 + 1/30 = 3+2/60 = 5 / 60, 5/60 = 1/12
if in one min they make 1/12 then in 12 min they paint all the wall