Answer:
C, Length = 39.4 cm; width = 7.9 cm
Step-by-step explanation:
The permimeter of a rectangle is 2 times the width + 2 times the length or 2(l + w)
The length is 4 times w plus 7.8.
So: 2w+2(4w+7.8)=94.6
= 2w+8w+15.6=94.6 (Factor out the brackets)
= 10w+15.6=94.6 (Combine like terms)
= 10w=79 (Subtract 15.6 from both sides)
= w=7.9 (Divide both by 10).
So, the width is 7.9 cm and the length is 39.4 cm (4 * 7.9 + 7.8)
Since 0.94 is the probability of both devices detecting, the probability of neither doing so is 1-0.94=0.06, answer 3.
