Aptitude - Problems on Numbers - Discussion
Discussion Forum : Problems on Numbers - General Questions (Q.No. 10)
10.
Find a positive number which when increased by 17 is equal to 60 times the reciprocal of the number.
Answer: Option
Explanation:
Let the number be x.
| Then, x + 17 = | 60 |
| x |
x2 + 17x - 60 = 0
(x + 20)(x - 3) = 0
x = 3.
Discussion:
21 comments Page 1 of 3.
Anitha Karre said:
5 years ago
In given options, suppose a positive number is 10.
Which is added by 17. i.e10+17=27 by a given question which is equal to 60. So see in the units place of both numbers (27,60) '7' & '0' which is not equal.
Suppose 3 is +ve number added by 17 gives 20 which is equal to 60/3=20.
So the positive number is 3.
Which is added by 17. i.e10+17=27 by a given question which is equal to 60. So see in the units place of both numbers (27,60) '7' & '0' which is not equal.
Suppose 3 is +ve number added by 17 gives 20 which is equal to 60/3=20.
So the positive number is 3.
(2)
Vasavi kota said:
8 months ago
Let's take the number is 'x'.
Increased by 17 = x + 17.
Which is equal to 60 times of reciprocal of the number i.e
x+17 = 60 x 1/x
x²+17x-60 = 0
x²+12x+5x-60 = 0
x(x+12)-5(x+12) = 0
(x+12)(x-5) = 0
Here x = -12(not taken)
So, x =5
Therefore the answer is 5.
Increased by 17 = x + 17.
Which is equal to 60 times of reciprocal of the number i.e
x+17 = 60 x 1/x
x²+17x-60 = 0
x²+12x+5x-60 = 0
x(x+12)-5(x+12) = 0
(x+12)(x-5) = 0
Here x = -12(not taken)
So, x =5
Therefore the answer is 5.
(4)
Joe said:
1 decade ago
Let the number be x but since we have 3,17,10 and 20 as the numbers but we don't know which is the correct one the here is the Equation,
x+17 = 60/x.
So am using 3 as my first number.
3(3+17) = 60/3*3.
3(20) = 20*3.
60 = 60.
Hence the Answer is 3.
x+17 = 60/x.
So am using 3 as my first number.
3(3+17) = 60/3*3.
3(20) = 20*3.
60 = 60.
Hence the Answer is 3.
Kausik said:
10 years ago
How you come to the assumption of x2+20x-3x-60 = 0 (we can write 17x as (20x-3x))?
20-3 = 17 is one of the assumptions for the result of 17, but how this can be narrowed to the right assumption?
20-3 = 17 is one of the assumptions for the result of 17, but how this can be narrowed to the right assumption?
(5)
Rakesh said:
1 decade ago
Find a positive number which when increased by 17 is equal to 60 times the reciprocal of the number.
But here you're not taking reciprocal of number to solve your just taking x.
But here you're not taking reciprocal of number to solve your just taking x.
Professor tajinder said:
1 decade ago
@Revathy
See we have (x-3)(x+20)=0
Now x-3=0
x=3
x+20=0
x=-20
But we have to find the postive no, so the answer is 3.
Hope you will undertand it.
See we have (x-3)(x+20)=0
Now x-3=0
x=3
x+20=0
x=-20
But we have to find the postive no, so the answer is 3.
Hope you will undertand it.
(1)
Debrupa said:
7 years ago
Reciprocal of x = 1/x.
Here, the equation should be ->
x+17=60*(1/x)
=> x=3,-20.
But, as we have to calculate +ve no only, so answer will be 3.
Here, the equation should be ->
x+17=60*(1/x)
=> x=3,-20.
But, as we have to calculate +ve no only, so answer will be 3.
(3)
Rajeev said:
1 decade ago
@Ravi we have to subdivide the equation.
We have x2 + 17x - 60 = 0,
Now, x2+20x-3x-60 = 0 (we can write 17x as (20x-3x)).
x(x+20)-3(x+20).
Then (x-3)(x+20) = 0.
We have x2 + 17x - 60 = 0,
Now, x2+20x-3x-60 = 0 (we can write 17x as (20x-3x)).
x(x+20)-3(x+20).
Then (x-3)(x+20) = 0.
Kabali said:
9 years ago
x2 + 12x + 5x - 60 = 0 also solution.
x(x + 12) - 5(x + 12) = 0.
Hence x = 5 is also the answer.
x(x + 12) - 5(x + 12) = 0.
Hence x = 5 is also the answer.
(3)
Revathy said:
1 decade ago
(x+20)(x-3)=0 is correct
hw did you arrive on x = 3?
Please explain the solving of equation.
hw did you arrive on x = 3?
Please explain the solving of equation.
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