Edward C. answered • 03/29/15
Tutor
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Caltech Grad for math tutoring: Algebra through Calculus
The variable x represents the number of people that Sanya gave money to, not the amount of money.
So if Sanya gave Rs100 to x people then he gave 100/x to each person.
If Vidushi gave Rs100 to (x+5) people then he gave 100/(x+5) to each person.
If Sanya gave each person Rs1 more than Vidushi then
(100/x) - 100/(x+5) = 1
When you solve for x you will find that x = 20, so x+5 = 25, therefore Sanya gave Rs5 to each person and Vidushi gave Rs4 to each person, and Rs5 - Rs4 = Rs1
Amey B.
have another question
4/7 of birthday cake was eaten on your birthday. The next day dad ate 1/2 of what was left. You get to finish the cake how much is left
in my book
let x be cake
x-4x/7 =3x/7
now 3x/7*1/2
answer come 3/14
my confusion is
4/7 of cake means 4/7 is part of cake so we took 4x/7
now when dad ate 1/2 part of remaining cake so it should be like this 3x/7*x/2 why i take x/2 because it is part of cake like previously but when i trying to solve this answer come 3x^2/14.
So for only first sentence why we took 4x/7 and second sentence took 1/2.
therefore how we know when to use x
please sent me detail information
4/7 of birthday cake was eaten on your birthday. The next day dad ate 1/2 of what was left. You get to finish the cake how much is left
in my book
let x be cake
x-4x/7 =3x/7
now 3x/7*1/2
answer come 3/14
my confusion is
4/7 of cake means 4/7 is part of cake so we took 4x/7
now when dad ate 1/2 part of remaining cake so it should be like this 3x/7*x/2 why i take x/2 because it is part of cake like previously but when i trying to solve this answer come 3x^2/14.
So for only first sentence why we took 4x/7 and second sentence took 1/2.
therefore how we know when to use x
please sent me detail information
Report
04/04/15
Edward C.
tutor
x is the amount of cake
(4/7) is the proportion (or fraction or percentage) of the cake that was eaten on your birthday. There is no x in (4/7). The x comes from multiplying the proportion that was eaten (4/7) by the amount of cake (x) to get (4/7)*x = 4x/7. If 4x/7 was eaten,
then x - 4x/7 = 7x/7 - 4x/7 = 3x/7 remains.
When dad eats (1/2) of what is left, there is no x in (1/2). The amount dad eats is the proportion he eats (1/2) times the amount of cake that is left (3x/7) which is (1/2)*(3x/7) = 3x/14 = (3/14)*x. The cake started as x and now (3/14)*x is left so
(3/14) of the cake is left.
Try doing an example. Suppose x = 14 slices of cake. (4/7) is eaten on your birthday, this is (4/7)*14 = 8 slices. So 14 - 8 = 6 slices remain. Then dad eats half of the 6 slices so he eats (1/2)*6 = 3 slices so now 6 -3 = 3 slices remain for you to
finish. 3 slices out of the original 14 is (3/14) left.
Report
04/05/15
Amey B.
4/7 of birthday cake was eaten on your birthday. The next day dad ate 1/2 of what was left. You get to finish the cake how much is left
in my book
let x be cake
x-4x/7 =3x/7
now 3x/7*1/2
answer come 3/14
my confusion is
4/7 of cake means 4/7 is part of cake so we took 4x/7
now when dad ate 1/2 part of remaining cake so it should be like this 3x/7*x/2 why i take x/2 because it is part of cake like previously but when i trying to solve this answer come 3x^2/14.
So for only first sentence why we took 4x/7 and second sentence took 1/2.
therefore how we know when to use x
please sent me detail information
04/03/15