Since she has seven key the probability that the first one will open the door is

if it takes three attempts to open the door,the probability is

if the three attempts would not work
then the probability that the fourth attempt will open the door is

hope this helps
Answer:I think the answer is
1. x=8
Step-by-step explanation:
1. X=8
2. X=1⅓
3. 0x=-12
4. -8x=0
5. 0x=24
It takes alvin 20 weeks, and it takes buzzy 15 weeks
Answer:
The base of the triangle is 6cm.
Step-by-step explanation:
The find the base of a triangle, use this formula.
Formula : 1/2 x b x h
<em>If you would like some more explanation, see the attached image.</em>