Three family members shared the cost of buying a flat equally. Adam used 1/2 of his savings, Bill used 6/7 of his savings and Carl used 3/4 of his savings. Bill and Carl had $44 820 left after paying for the flat.
(a) How much did the flat cost?
(b) How much does each of them have at first?
It's actually easier to answer (b) first
Let A = the amount that Adam started with
Let B = the amount that Bill started with
Let C = the amount that Carl started with
We know that, since each paid an equal amount, then
(1/2) A = (6/7)B = (3/4) C
Which implies that
A = (2/1)(6/7)B = (12/7)B
C = (4/3)(6/7)B = (24/21)B = (8/7)B
And we know that
(1/7)B + (1/4)C = 44820
So....subbing for C ,we have
(1/7)B + (1/4)(8/7)B = 44820
( 1/7)B + (8/28)B = 44820
( 1/7)B + ( 2/7)B = 44820
(3/7)B = 44820 mult both sides by 7/3
B = 44820 (7/3) = $104580 what Bill started with
A= (12/7)(104580) = $179280 what Adam started with
C = (8/7)(104580) = $119520 what Carl started with
And the flat cost
(6/7)(104580) + (1/2)(179280) + (3/4)(119520) =
$89640 + $89640 + $89640 =
$268920
Let C - total rest of the flat
x - Adam's savings
y - Bill's savings
z - Carl's savings
Thus we know
C = 1/2x + 6/7y + 3/4z
Where 1/2x = 4/7y = 3/4z
Because the three of them shared the cost equally.
Now, y + z - 6/7y - 3/4z = 44,820
1/7 + 1/4z = 44,820,
Since 6/7y = 3/4z,
z = 4/7 (y)
z = 8/7y
Hence,
1/7y + 1/4 (y) = 44,820
1/7 + 2/7y = 44,820
3/7y = 44,820
y = 7/3 (44,820)
y = 104,580
Since z = 8/7y
z = 8/7 (104,580)
z = 119,520
Also,
Since 1/2x = 6/7y,
x = 2(6/7)y
x = 12/7y
x = 12/7 (104,580)
x = 179,280
Now, the total cost of the flat is
C = 1/2x + 6/7y + 3/4z
C = 1/2 (179,280) + 6/7 (104,580) + 3/4 (119,520)
C = 89,640 + 89,640 + 89,640
C = 268,920
Thus, the answers should be
(a) $268,920
(b) Adam's savings: $179,280
Bill's saving: $104,580
Carl's savings: $119,520