Video Transcript
A business woman went to her
company on Wednesday morning at the time shown below. She had a lot of work, and it took
her 12 hours to finish it. At what time did she finish?
And we can see that we’ve got four
different answers to choose from here. Let’s go through the question
carefully and try to pick out the important information. To begin with, we’re told that a
business woman went to her company on Wednesday morning. This is important because three of
our answers show times on Wednesday, and one shows a time on Thursday. So, the day and the time of day are
important here. But we’re also given more
information than this. We’re told the exact time that this
lady goes to her company. It’s the time on the clock.
What time did she go to work? The minute hand on this clock face
is pointing to the six. It’s gone half the way around the
clock face, and so we know it’s a half past time. The hour hand is halfway between
the number eight and nine. And so, we know it’s half the way
past 8 o’clock on its way to 9 o’clock. The time is half past 8. So, we’re told that this lady goes
to work at half past 8 in the morning.
We’re then told that she had a lot
of work to do, and it took her 12 hours to finish it. That’s quite a long workday. Now, this amount of time, 12 hours,
is important. What do we know about 12 hours? We know that 12 hours is the length
of time it takes for the hour hand to start from a position on the clock face and go
all the way around back to where it started. And we can use this fact to help
us. As we’ve said already at half past
8 in the morning, the hour hand is halfway between the number eight and nine. And so, 12 hours later, when this
lady finishes her work, it’s going to be halfway between the eight and the nine
again. The time will be half past 8
again.
If we look at our first possible
answer, we can see that the clock shows half past 8 on Wednesday. And if we look at the window, we
can see the sun is up in the sky. It looks like it’s Wednesday
morning, doesn’t it? This lady doesn’t finish her work
on Wednesday morning at half past 8; this is when she starts work. So this isn’t the right answer. But you know, we’ve got another
morning time in our answers too. This one shows Thursday morning at
half past 8. Now, if it only took 12 hours to
get from Wednesday morning at half past 8 to Thursday morning at half past 8, then
we could say that there are 12 hours in a day, but we know there are 24 hours in a
day. So if this lady was to finish our
work at half past 8 in the morning the next day, that would mean she’d spent 24
hours on it, not 12.
So, we’re left with two possible
answers. We know that we’re looking for a
half past 8 time. And both of these pictures show
Wednesday night. We can see that because the moon’s
out in the sky. Now, which one of our clocks shows
half past 8? It’s this one, isn’t it? The minute hand is pointing to the
six, and the hour hand is halfway between the eight and the nine. Let’s not make the mistake of
choosing this answer. If you look at this clock, we can
see that the minute and the hour hand have been swapped around. We don’t wanna get them muddled up,
do we? The time that is 12 hours later
from Wednesday morning at half past 8 is Wednesday evening at half past 8.
