SOLUTION: Please help me with this math question on fraction.Thank you in advance. {{{3/20}}} of the bottled water in a supermarket were sold on Monday. 90 fewer bottles of water were sold

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: Please help me with this math question on fraction.Thank you in advance. {{{3/20}}} of the bottled water in a supermarket were sold on Monday. 90 fewer bottles of water were sold      Log On


   

Question 1187442: Please help me with this math question on fraction.Thank you in advance.
3%2F20 of the bottled water in a supermarket were sold on Monday.
90 fewer bottles of water were sold on Tuesday than on Monday. 70
fewer bottles of water were sold on Wednesday than on Tuesday. On
Thursday, 330 bottles of water were sold. The number of bottles of
water left in the supermarket was 1%2F2 the number of bottles there was
at first. How many bottles of water were there in the supermarket at
first?
Found 2 solutions by MathLover1, MathTherapy:
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

let the number of the bottles of water be x
%283%2F20%29x were sold on Monday
90+fewer bottles of water were sold on Tuesday than on Monday:
%283%2F20%29x-90were sold on Tuesday
70 fewer bottles of water were sold on Wednesday than on Tuesday,
%283%2F20%29x-90-70=>%283%2F20%29x-160 were sold on Wednesday

On Thursday, 330 bottles of water were sold.
The number of bottles of water left in the supermarket was 1%2F2 the number of bottles there was at first.
%281%2F2%29x left in the supermarket
add all and equal to x
%283%2F20%29x%2B%283%2F20%29x-90%2B%283%2F20%29x-160%2B330%2B1%2F2%29x=x .......solve for x
%2819x%29%2F20+%2B+80=x
19x+%2B+80%2A20=20x
1600=20x-19x
x=1600+ ->bottles of water were there in the supermarket at
first

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!
Please help me with this math question on fraction.Thank you in advance.
3%2F20 of the bottled water in a supermarket were sold on Monday.
90 fewer bottles of water were sold on Tuesday than on Monday. 70
fewer bottles of water were sold on Wednesday than on Tuesday. On
Thursday, 330 bottles of water were sold. The number of bottles of
water left in the supermarket was 1%2F2 the number of bottles there was
at first. How many bottles of water were there in the supermarket at
first?
Let original number of bottles be B
Amount sold on 

Total sold in 4 days: 

With matrix%281%2C3%2C+%281%2F2%29B%2C+or%2C+B%2F2%29 remaining, we can say that: 
20B - 9B - 20(80) = 10B ------ Multiplying by LCD, 20 
     11B - 20(80) = 10B
         - 20(80) = 10B - 11B
         - 20(80) = - B
Original number of bottles, or