Answer:
$400
Explanation:
Let the initial total cost be represented = $X.
Hence, for 20 family members
= $ x/20 each .......1
Now that they are 25 members
= $x/25 each.......2
Each in the original group which is equation 1 owed $4 less.
That is,
x/20 - 4 ........ 3
Now equate 2 and 3
X/20 - 4/1 = X/25
Taking the LCM of both sides
X-80/20 = X/25
Cross multiply both sides
25( x-80 ) = 20x
25x-2000 = 20x
Collecting like terms
25x-20x = 2000
5x = 2000
Divide through by 5
X = 2000/5
X = 400
The total cost for the catered meal is $400.
To check if it was correct
Put 400 into equation 1 and 2 and then minus whatever you get from each other, you will get $4
From equation 1
400/20 = $20
From equation 2
400/25 =$16
$20-$16 = $4
Thanks