a fraction becomes 9/11 of 2 is added to denominator and numerator if 3 is added to both numerator and denominator it becomes 5/4 find fraction
Answers
Question:
A fraction becomes 9/11 if 2 is added to the denominator and numerator and if 3 is added to both numerator and denominator it becomes 5/6. Find the fraction.
Answer:
Step-by-step explanation:
- A fraction becomes 9/11 if 2 is added to both numerator and denominator
- A fraction becomes 5/6 if 3 is added to both numerator and denominator.
- The fraction
→ Let the numerator of the fraction be x
→ Let the denominator of the fraction be y
→ Hence,
The fraction = x/y
→ In the first case, the fraction becomes 9/11 if 2 is added to both numerator and denominator
→ Hence,
→ Cross multiplying,
11 ( x + 2) = 9(y + 2)
11x + 22 = 9y + 18
9y = 11x + 22 - 18
9y = 11x + 4
9y - 11x = 4 ------(1)
→ In the second case, if 3 is added to the numerator and denominator, the fraction becomes 5/6
→ Hence,
→ Cross multiplying,
6 (x + 3) = 5 (y + 3)
6x + 18 = 5y + 15
6x - 5y = -3
5y - 6x = 3---(2)
→ Multiply equation 1 by 5 and equation 2 by 9
45y - 55x = 20
45y - 54x = 27
→ Solving by elimination method,
-x = -7
x = 7
→ Hence the numerator of the fraction is 7
→ Substitute the value of x in equation 1
9y - 11 × 7 = 4
9y -77 = 4
9y = 81
y = 9
→ Hence the denominator of the fraction is 9
→ Therefore,
The fraction = 7/9
(7 + 2)/(9 + 2) = 9/11
9/11 = 9/11
(7 + 3)/(9 + 3) = 5/6
10/12 = 5/6
5/6 = 5/6
→ Hence verified.
Information :- This solution is based on Cross Multiplication.
Given :-
Fraction becomes 9/11 if 2 is added to both numerator and denominator.
If 3 is added to both numerator and denominator it becomes 5/6.
Solution:-
Let the Numerator be x
Let the Denominator be y
Fraction = x/y
According to the Question,
⇒ (x + 2)/y + 2 = 9/11
On Cross multiplying,
⇒ 11x + 22 = 9y + 18
Subtracting 22 from both sides,
⇒ 11x = 9y – 4
Dividing by 11, we get
⇒ x = 9y – 4/11 … (i)
Then,
⇒ (x+3)/y +3 = 5/6 … (ii)
On Cross multiplying,
⇒ 6x + 18 = 5y + 15
Subtracting the value of x, we get
⇒ 6(9y – 4 )/11 + 18 = 5y + 15
Subtracting 18 from both the sides
⇒ 6(9y – 4 )/11 = 5y – 3
⇒ 54 – 24 = 55y – 33
⇒ –y = – 9
⇒ y = 9
Putting this value of y in equation (i), we get
⇒ x = 9y – 4
⇒ x = (81 – 4)/77
⇒ x = 77/11
⇒ x = 7