SOLUTION: Mr White purchased some bottles of mineral water for his son. After a week, he used 4/7 of the bottles leaving 6 bottles. (i) Find the fraction of the bottles of mineral water t

Algebra ->  Real-numbers -> SOLUTION: Mr White purchased some bottles of mineral water for his son. After a week, he used 4/7 of the bottles leaving 6 bottles. (i) Find the fraction of the bottles of mineral water t      Log On


   



Question 1195902: Mr White purchased some bottles of mineral water for his son. After a week, he
used 4/7 of the bottles leaving 6 bottles.
(i) Find the fraction of the bottles of mineral water that remain after a week.
(ii) How many bottles of mineral water did he purchased that week?

Answer by math_tutor2020(3817) About Me  (Show Source):
You can put this solution on YOUR website!

He uses 4/7 of the bottles, so he must have 3/7 of them left.
x = number of bottles purchased

3/7 of x = (3/7)x = 6 bottles left

Solve for x.
(3/7)x = 6
3x = 6*7
3x = 42
x = 42/3
x = 14

If he bought 14 bottles and has 6 left over, then he must have used 8 of them (14-6 = 8).
Note how 8/14 = (2*4)/(2*7) = 4/7 represents the fraction of the bottles used up to confirm we have the correct x value.


Answers:
(i) 3/7
(ii) 14