a : b = 4 : 9. If 4 is added to both of the numbers then the new ratio becomes 21 : 46.
Posted on 06-02-2023
Ques - a : b = 4 : 9. If 4 is added to both of the numbers then the new ratio becomes 21 : 46. What is the difference between a and b?
(a) 80
(b) 100
(c) 125
(d) 130
Solution -
a : b = 4 : 9
Let,
a = 4x
b = 9x
If 4 is added to both of the numbers then the new ratio becomes 21 : 46.
(4x + 4)/(9x + 4) = 21/46
46 (4x + 4) = 21(9x + 4)
184x + 184 = 189x + 84
184 - 84 = 189x - 184x
100 = 5x
x = 20
Therefore,
a = 4x
a = 4(20)
a = 80
b = 9x
b = 9(20)
b = 180
So,
b - a = 180 - 80
= 100
Thus,
The difference between a and b is 100.
Hence,
The correct answer is option (b) 100.
Thank You