Thrice a number is added to itself.If the sum thus obtained is written 20 times and added,the total is 400.Find the number
2006-09-30 03:28:37 · 19 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
(x+3x)*20=400
4x=400/20
4x=20
x=20/4
x=5
2006-09-30 03:34:57 · answer #1 · answered by no one 6 · 2⤊ 1⤋
Hi. Start with the answer. 400 / 20 will equal a number. This number is 4 times the number you are looking for. (Thrice is 3 add one is four.) The above answers are not correct.
2006-09-30 03:34:26 · answer #2 · answered by Cirric 7 · 2⤊ 1⤋
x = the number
x + 3x = three times the number when added
20(x + 3) = twenty times when added
400 = The total
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The equation
20(x + 3x) = 400
20( 4x ) = 400
80x = 400
80x/80 = 400/80
x = 5
The answer is x = 5
The solution set is { 5 }
Insert the x value into the equation
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Check
20(x + 3x)= 400
20[5 + 3(5)] = 400
20[5 + 15]= 400
20[20] = 400
400 = 400
2006-09-30 08:01:01 · answer #3 · answered by SAMUEL D 7 · 1⤊ 0⤋
Let x be the number
Thrice the number plus itself is 3x + x
Since it must be written 20 times and then be added, we will have
20(3x + x)
The equation then is
20(3x + x) = 400
60x + 20x = 400
80x = 400
x = 5
Therefore, the answer is 5.
2006-09-30 03:43:33 · answer #4 · answered by pterocarpus_indicus05 2 · 0⤊ 0⤋
Let the number be x
According to question
(3x+x)X20=400
4x=400/20
4x=20
x=5
Therefore the number is 5
2006-09-30 03:59:00 · answer #5 · answered by dudul 2 · 1⤊ 0⤋
Yawn....
1)Let the number be Z.
2) 3Z+Z=4Z (Thrice a number is added to itself.
3) 4Z x 20=80Z (If the sum thus obtained is written 20 times and added)
4) 80Z=400 so...........................
5) Z=5
The mysterious number is 5
2006-09-30 03:40:33 · answer #6 · answered by TheErrandBoy 2 · 1⤊ 1⤋
I guess the number must be 5.
According to you:
(3x+x) * 20 = 400
=> 4x = 20
=> x = 5
I wonder in which class you study.
2006-09-30 03:39:22 · answer #7 · answered by Rahul Ghose 4 · 0⤊ 2⤋
You question is a little unclear
400/20=20
3x+x=20
4x=20
x=5
or you might mean
((3x)+(3x))20=400
(6x)20=400
6x=20 20/6 = 3&1/3
2006-09-30 04:36:52 · answer #8 · answered by Roy 3 · 0⤊ 1⤋
no. is equal to x.
3x+x=4x
20(4x)=80x
80x=400
x=400 divided by 80 =5
2006-09-30 03:44:54 · answer #9 · answered by sim 2 · 1⤊ 0⤋
20/3+20/3+20/3=20
20X20=400
2006-09-30 03:31:51 · answer #10 · answered by prusa1237 7 · 0⤊ 2⤋
Hi there !
Let the number be "x"
{ 3x + 3x } 20 = 400
ie : 60x + 60x = 400
ie : 120x = 400
ie : 12x = 40
ie : x = 40 / 12
ie : x = 10 / 3 = 3.33
???
2006-09-30 03:35:24 · answer #11 · answered by suresh k 6 · 1⤊ 1⤋