Dividing fractions word problems (ex 1) - Fraction, Arithmatic, Mathematics Video Lecture - JEE

da thought it would be nice to include
221st
of a pound of chocolate in each of the
holiday gift bags she made for her
friends and family so Dee is very
precise she was exactly to 21st of a
pound of chocolate how many how many
holiday gift bags could de make with 2/3
of a pound of chocolate so we really
just need to think about what's the
total amount what's the total amount of
chocolate she has so what's the total
pounds and we just have to divide it by
the pounds she wants per bag pounds
pounds per bag and then you will get the
number of bags number of number of bags
if she had six total pounds and she
wanted two pounds per bag she would be
able to make three bags and so we just
do the same thing over here but over
here her total number of pounds it's a
slightly hairier number it's two thirds
so her total pounds are two thirds of a
pound we want to divide that by how many
pounds she wants to put in each bag so
that would be to 21st to 21st of a pound
and this will give us the number of bags
now when we divide fractions like this
so we can rewrite this expression this
is the same thing as 2/3 divided by 220
first 2 over 21 which we've learned is
the same thing as which is the same
thing as 2/3 2/3 times the reciprocal of
221st which is just 21 over 2 21 over 2
all we did is we swapped the numerator
and the denominator we took the
reciprocal here when you divide by a
fraction it's like multiplying by its
reciprocal and this is equal to and
there's other videos we would go into
the idea behind that we just have to
multiply this out in our numerator and I
won't even multiply it out in our
numerator we get 2 times 21 I'll do a
new color here 2 times 21 when I
multiply the numerators and the
denominator I get 3 times 2 and now we
can simplify it before we even multiply
it out divide the numerator in the
denominator by a common factor they're
both divisible by 2 they are both
divisible by 2 so let's divide both the
numerator and denominator by 2
the numerator denominators both
divisible by three 21s dividable by
three and three is divisible by three so
let's to also divide them both by three
so when you divide the numerator by 2 so
this 2 and this 2 cancels out and then
21 divided by 3 you're just left with
seven down here you have 2 divided by 2
cancels out and 3 divided by 3 cancels
out and so you're left with 7 over 1 or
exactly 7 7 bags