Need to be done ✅

there is a total of 270 men, women and children on a train.
the ratio of men to women is 4 : 5.
the ratio of women to children is 10:
how many men are on the train?
give your final answer as
.. men on the train.

80 men

Step-by-step explanation:

Let m represent the number of men , w , the number of women and c the number of children , then we have:

m : w = 4 : 5 equation 1

w : c = 10 : 9 equation 2

Multiply equation 1 by 2 so as to get the ratio m:w:c , that is

equation 1 becomes : m: w = 8 : 10

so the combine ration m : w : c is 8 : 10 : 9

The total ratio is therefore 8 + 10 + 9 = 27

number of men = ratio of men/ total ratio X 270

number of men = 8/27 X 270

number of men = 8 X 10

number of men = 80

i think it's eleven too, don't woosh me here, but according to the "experts" it's 2.

the proof starts from the peano postulates, which define the natural

numbers n. n is the smallest set satisfying these postulates:

  p1.   1 is in n.

  p2.   if x is in n, then its "successor" x' is in n.

  p3.   there is no x such that x' = 1.

  p4.   if x isn't 1, then there is a y in n such that y' = x.

  p5.   if s is a subset of n, 1 is in s, and the implication

      (x in s => x' in s) holds, then s = n.

then you have to define addition recursively:

  def: let a and b be in n. if b = 1, then define a + b = a'

      (using p1 and p2). if b isn't 1, then let c' = b, with c in n

      (using p4), and define a + b = (a + c)'.

then you have to define 2:

  def:   2 = 1'

2 is in n by p1, p2, and the definition of 2.

theorem:   1 + 1 = 2

proof: use the first part of the definition of + with a = b = 1.

      then 1 + 1 = 1' = 2   q.e.d.

note: there is an alternate formulation of the peano postulates which

replaces 1 with 0 in p1, p3, p4, and p5. then you have to change the

definition of addition to this:

  def: let a and b be in n. if b = 0, then define a + b = a.

      if b isn't 0, then let c' = b, with c in n, and define

      a + b = (a + c)'.

you also have to define 1 = 0', and 2 = 1'. then the proof of the

theorem above is a little different:

proof: use the second part of the definition of + first:

      1 + 1 = (1 + 0)'

      now use the first part of the definition of + on the sum in

      parentheses:   1 + 1 = (1)' = 1' = 2   q.e.d.

a sample of water is taken and kept in a beaker in a freezer at a constant temperature of 0°c. if the system is at dynamic equilibrium, which of these statements is true?