The cumulative frequency curve below shows the time Mr Smith
takes to travel to work over 300 days. What is the estimate of the
probability that his journey takes more than 25 minutes on 1 day
and less than 25 minutes the next day?
Whether it's less than 25 or more than 25 minutes both are at
150 days. So I used 150/300 X 150/299?? Seems to get the wrong
answer. May I know where I went wrong?
2. In a family of 5, the probability sue reaches home first is
7/12 and probability joe reaches home first is 1/12. Find the
probability that either sue or joe is first home. My answer to to
just add the 2 values together. Just to double check, is it
right?
3. 
Here's what I did.
3 X (15/50 X 14/49 X 35/48) = 3/16
Is my answer correct? I multiplied by 3 because the dogs couldbe
chosen in the following orders. X represents more than 12 cm while
y reps less than 12cm.
( x,x,y) (y,x,x),(x,y,x)
thanks