two numbers are such that the ratio is 3 is to 5 if each is increased by 10 the ratio between the New numbers so formed is 5 is to 7.find the original numbers
Answers
Answer:
x = 5
3x = 15
5x = 25
Step-by-step explanation:
The ratio between two numbers is : 3:5
Let 3 be 3x and 5 be 5x.
Then,
3x+10:5x+10 = 5:7
The same written in fractional form=
3x/5x + 10/10 = 5/7
7(3x+10) = 5(5x+10)
21x + 70 = 25x + 50
21x - 25 = 50 - 70
4x = 20
x = 20/4
x = 5
3x = 15
5x = 25
Question : -
Two numbers are in the ratio of 3 : 5 . If each number is increased by 10 the ratio of the new numbers which are formed will be in the ratio of 5 : 7 .
Find the original number ?
Given : -
Two numbers are in the ratio of 3 : 5 .
If each number is increased by 10 the ratio of the new numbers which are formed will be in the ratio of 5 : 7 .
Required to find : -
- Original number ?
Solution : -
Two numbers are in the ratio of 3 : 5 .
If each number is increased by 10 the ratio of the new numbers which are formed will be in the ratio of 5 : 7 .
We need to find the original number .
So,
Given ratio = 3 : 5
Now,
Let the 1st number be 3x
2nd number be 5x
Here,
x is a variable which represents an unknown value .
If we are able to calculate the value of x then we can find the original number .
However,
a : b = a/b ( a : b can also be written as a/b )
This implies ;
Ratio of the two numbers = 3x/5x
Now,
According to the 2nd statement .
If each number is increased by 10 the ratio of the new numbers which are formed will be in the ratio of 5 : 7 .
So,
Let the 1st number be 3x + 10
2nd number be 5x + 10
According to the condition ;
These two numbers when increased by 10 will be equal to ratio 5 : 7
This implies ;
By cross multiplication we get ;
7 ( 3x + 10 ) = 5 ( 5x + 10 )
21x + 70 = 25x + 50
21x - 25x = 50 - 70
- 4x = - 20
Taking - ( minus ) common on both sides
- ( 4x ) = - ( 20 )
- ( minus ) get's cancelled on both sides
4x = 20
x = 20/4
x = 5
Hence,
- Value of x = 5
Now,
By substituting these value x in place of x in the assumed values
This implies ;
1st number = 3x
=> 3 ( 5 )
=> 15
2nd number = 5x
=> 5 ( 5 )
=> 25
Therefore,
The original number are 15 & 25 .
Verification : -
Let's verify whether our calculations are correct or wrong .
For that , let's consider the 2nd statement .
According to which ;
The two numbers when increased by 10 will be equal to ratio 5 : 7
So,
The two numbers will thus become as ;
15 + 10 = 25
25 + 10 = 35
This implies ;
25 : 35 = 5 : 7
By reducing using the 5 table we get ;
5 : 7 = 5 : 7
LHS = RHS