Not that hard
Level
pending
If x,y and z are positive integers and 3x=4y=7z, then what is the least possible value of x+y+z ?
The answer is 61.
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1 solution
We have 3x=4y=7z
this means that 3x, 4y, and 7z are all equal to some number let's call it "n"
this also means that 3x=n
4y=n
7z=n
From this, we can see that "n" must be a multiple of 3,4, and 7. What is the smallest multiple of 3,4, and 7 ? It is 84
( 3)(4)(7) = 84
3x=84>> x=28
4y=84>> y= 21
7z=84>>z=12
x+y+z=28+21+12= 61