8. Two numbers are such that the ratio between them is 3:5. If each is increased by 10, the
ratio between the new numbers so formed is 5 : 7. Find the original numbers.
Answers
Answer:
Step-by-step explanation:
Given The ratio of the 2 no. is = 3:5
Let the no. be 3x and 5x
If each one is increased by 10
They wil become = 3x + 10 and 5x + 10
A/Q,
3x + 10 / 5x + 10 = 5 / 7
7 ( 3x + 10) = 5 ( 5x + 10)
21x + 70 = 25x + 50
21x - 25x = 50 - 70
- 4x = -20
x = 20 / 4
So, x = 5
Now,
The no. are =3x
= 3 × 5
= 15
And
5x
= 5 × 5
= 25
ratios of numbers = 3 : 5
let the constant ratios be x
ratios now become = 3x : 5x
after adding 10 to both the rational sides ==>
3x + 10 : 5x + 10 = 5x : 7x
let the ratios be put in fractional form.
3x + 10 = 5x
5x + 10 = 7x
cross multiplication
7x ( 3x + 10 ) = 5x ( 5x + 10 )
=> 21x^2 + 70x = 25x^2 + 50x
=> 21x^2 - 25x^2 = 50x - 70x
=> -4x^2 = -20x
=> 4x^2 = 20x
=> x^2 = 20x/4
=> x^2 = 5x
=> x * x = 5 * x
=> x = 5
number 1 = 3x = 3 * 5 = 15
number 2 = 5x = 5 * 5 = 25