100y+x=230
150y+x=320
Y being the price per kilogram of steel bar, x being the added delivery fee.
If you were to solve the equaltion it would go x=230-100y by changing the first equation around the replacing that for the x int he second group, so you would get 150y+230-100y=320 or 50y=90 So Y=9/5dollars per kilogram. Or $1.8per kilogram, the delivery fee being $50
$68
divide 8 by 2 to get 4
multiply 17 times 4 to get 68
The lowest common multiple of 3, 5, and 7 is 105, so
that's the smallest number that has those prime factors.
Every multiple of 105 is another one:
210, 315, 420, etc.
So is (105) times (any multiple of 3 or 5 or 7):
(x 3, 6, 9) 315, 630, 945, etc.
(x 5, 10, 15) 525, 1050, 1575, etc.
(x 7, 14, 21) 735, 1470, 2205, etc.
What is the acutal question
1/8 = 12.5 and 3/4 = 75 so he can wash 6 times before running out.