Answer:

Step-by-step explanation:
Given that a shuttle launch depends on three key devices that may fail independently of each other with probabilities 0.01, 0.02, and 0.02, respectively.
Required probability = the probability for the shuttle to be launched on time
= Probability that all three do not fail
Since each key device is independent of the other
we have
prob that all three do not fail = 
Answer:
second option
Step-by-step explanation:
x - y= 28
x+y = 56
<em>3 minus ___</em> ⇒ 3 - ___
<em>the product of 2 and a number x</em> ⇒ 2x
"3 minus the product of 2 and a number x" ⇒ 3 - 2x
_____
Each part of the description has a translation.
It is a whole number, and is positive