Question 256063: On Friday, the With-It Clothiers sold some jeans at $25 a pair and some shirts at $18 each. receipts for the day totaled $441. On Saturday the store priced both items at $20, sold exactly the same number of each item, and had receipts of $420. How many pairs of jeans and how many shirts were sold each day?
if some tutor cold help me applying a algebra formula or some this would be very helpful though i can solve the problem i would really want to know how to solve it by algebra means THANKS!
Found 2 solutions by CharlesG2, richwmiller:
Answer by CharlesG2(834)   (Show Source):
You can put this solution on YOUR website! On Friday, the With-It Clothiers sol some jeans at $25 a pair and some shirts at $18 each. receipts for the day totaled $441. On saturday the store priced both items at $20, sol exactly the same number of each item, and ha receipts of $420. how many pairs of jeans an how many shirts were sold each day?
J=number of jeans , S=number of shirts
25*J+18*S=441
20*J+20*S=420
solve second equation for either J or S and use subsitution, am gonna choose J
20*J=420-20*S
J=21-S (plug this into 1st equation and solve for S)
25(21-S)+18*S=441
25*21 - 25*S +18*S = 441
25*21 -7*S = 441 (25*21=525)
-7*S = 441 - 525
-7*S = -84
S = 12 shirts (plug this into 2nd equation and solve for J)
20*J+20*12=420 (divide by 20)
J+12=21
J=9 pairs of jeans
Answer by richwmiller(17219)  (Show Source):
You can put this solution on YOUR website! So how did you solve it, if not by algebra?
25x+18y=441
By graphing we see that integers are 9 for x and 12 for y
25*9+12*18=441
225+216=441
or we can substitute x's and y's and find integers
y=(441-25x)/18
y = 49/2-(25x)/18
we also know that x is either odd or even
if even then 25x ends in 0
if odd then 25x ends in 5
so we need 18y that ends in 1 441-1 so 25x can end in 0 or 6 so 25x can end in 5
There are none that end in 1 so x must be odd
18*2=36 441-36=405 not divisible by 25
18*7=126 441-26=415 not divisible by 25
18*12=216 441-216=225 9*25=225
25q=450=18 so x can be max of 17
25*18=450
so y can be 24 max
1
1
x must be odd
y ends in 2 or 7
x=1,3,5,7,9,11,13,15,17
y=2,7,12,17,22
20z+20z=420
40z=420
4z=42
2z=21
z=10.50
So either your numbers are wrong or they sold half a pair of jeans and half a shirt.
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