The numerator of a fraction is 5 less than its denominator. If 1 is added to the numerator and to the denominator, the new fraction is 2/3. Find the fraction.
Answers
9/14
Step-by-step explanation:
Let the original denominator be 'x'. So, numerator is 5 less than x = x - 5.
Fraction is (x - 5)/x
When 1 is added to the numerator and to the denominator. Denominator is (x + 1) and numerator is (x - 5) + 1 = (x - 4).
Fraction is 2/3 :
=> (x - 4)/(x + 1) = 2/3
=> 3(x - 4) = 2(x + 1)
=> 3x - 12 = 2x + 2
=> 3x - 2x = 12 + 2
=> x = 14
Original fraction = (x - 5)/x = (14 - 5)/14
Original fraction is 9/14
Given that:
⋆ The numerator of a fraction is 5 less than its denominator.
⋆ 1 is added to the numerator and to the denominator.
⋆ The new fraction is 2/3
To find: The original fraction.
Solution: The original fraction = 9/14
Assumption: Let denominator be a
Full Solution:
• As we already take a as the denominator. As it is given that the numerator of a fraction is 5 less than its denominator henceforth, let us assume numerator as a-5. Henceforth, as we know that a fraction is consists of a numerator and denominator. Henceforth, fraction be (a-5)/a
• Also given that 1 is added to the numerator and to the denominator henceforth, now it be the following:
- Numerator = (a-5)+1 = a-4
- Denominator = a+1 = (a+1)
• Now given that the new fraction is 2/3. Now let's put the values.
→ 2/3 = (a-4)/(a+1)
◕ Cross multiplying we get,
→ 3(a-4) = 2(a+1)
→ 3a - 12 = 2a + 2
→ 3a-2a = 2+12
→ 1a = 14
→ a = 14
- We get denominator as 14.
• Henceforth, original fraction be
→ (a-5)/a
→ (14-5)/14
→ 9/14
- Original fraction is 9/14