what number decreased by 33and1/3% is 30?
show all work plz
2007-01-29 09:25:25 · 7 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
x-(1/3)x=30
3x-x=90
2x=90
x=45
2007-01-29 09:32:05 · answer #1 · answered by Professor Maddie 4 · 0⤊ 0⤋
I find it easiest to translate percent problems into words, then solve for the variable. Let x be the number. So x minus 33 1/3% of x gives you 30. This means:
x - (33 1/3%)x = 30
33 1/3% is just one third of 100%, so as a fraction you can write it as 1/3:
x - (1/3)x = 30
x(1 - 1/3) = 30
x(3/3 - 1/3) = 30
x(2/3) = 30
x = 30*(3/2)
x = 45
2007-01-29 09:33:17 · answer #2 · answered by Anonymous · 0⤊ 0⤋
2/3*x=30 x=45
2007-01-29 09:30:58 · answer #3 · answered by bruinfan 7 · 1⤊ 1⤋
x - x/3 = 30
multiply by 3: 3x - x = 90
simplify: 2x = 90
divide by 2: x = 45
so 45 when decreased by 33.3% is 30.
2007-01-29 09:32:10 · answer #4 · answered by noshyuz 4 · 0⤊ 0⤋
45 - (1/3)(45) = 45 - 15 = 30
2007-01-29 09:29:37 · answer #5 · answered by Doctor J 7 · 0⤊ 2⤋
1.) n - 0.30 = 120 n = 120.3 2.) 50%n + n = 120 0.50n = 120 n = 240
2016-03-29 08:37:43 · answer #6 · answered by Michele 4 · 0⤊ 0⤋
Assume number is x.
x - (33.33% * x) = 30
x=45
2007-01-29 09:31:00 · answer #7 · answered by Fahd Shariff 3 · 0⤊ 0⤋