2. What should be added to the ratio 5 : 11, so that the ratio becomes 3 : 4?
3. Two numbers are in the ratio 7 : 5. If 2 is subtracted from each of them,
the ratio becomes 3 : 2. Find the numbers.
4. Two numbers are in the ratio 3: 7. If their sum is 710, find the numbers.
5. Find the ratio of A : B: C when
(a) A: B = 3:5 A: C = 6:7
(b) B: C = 1/2: 1/6 A:B = 1/3 : 1/5
Answers
2.
Let the numbers be 5x and 11x.
By adding y to the ratio becomes 4 : 5
➣ ( 5x + y ) : ( 11x + y ) = 3 : 4
➣ 4(5x + y) = 3(5x + y)
➣ 20x + 4y = 15x + 3y
➣ 20x - 15x = -4y + 3y
➣ 5x = -y
3.
To Find:-
- Find the two numbers.
Solution:-
Given,
- Two numbers are in ratio of 7 : 5 and if 2 is subtracted the ratio of them will be 3 : 2.
Let the two numbers be 7x and 5x.
➣ (7x - 2)/(5x - 2) = 3/2
➣ 2(7x - 2) = 3(5x - 2)
➣ 14x - 4 = 15x - 9
➣ 9 - 4 = 15x - 14x
➣ x = 5
➣
Therefore the value of x = 5
So,
The numbers are 7x = 7(5) ⟹ 35
The numbers are 5x = 5(5) ⟹ 25
Verification:-
Th ratio become 3 : 2 = 35 +
- 2 => 33
25 - 2 => 22
∴ The numbers are 33 and 22.
4.
Given:-
- Two numbers are in the ratio 3: 7 and their sum is 710.
Let the unknown number be x
3x + 7x = 710
10x = 710
x = 710/10
x = 71
Verification:-
3(71) + 7(71) = 710
213 + 497 = 710
710 = 710
Let the numbers be 5x and 11x.
By adding y to the ratio becomes 4 : 5
➣ ( 5x + y ) : ( 11x + y ) = 3 : 4
➣ 4(5x + y) = 3(5x + y)
➣ 20x + 4y = 15x + 3y
➣ 20x - 15x = -4y + 3y
➣ 5x = -y
Two numbers are in ratio of 7 : 5 and if 2 is subtracted the ratio of them will be 3 :
Let the two numbers be 7x and 5x.
➣ (7x - 2)/(5x - 2) = 3/2
➣ 2(7x - 2) = 3(5x - 2)
➣ 14x - 4 = 15x - 9
➣ 9 - 4 = 15x - 14x
➣ x = 5
➣ x=5
Therefore the value of x = 5
So,
The numbers are 7x = 7(5) ⟹ 35
The numbers are 5x = 5(5) ⟹ 25
Let the unknown number be x
3x + 7x = 710
10x = 710
x = 710/10
x = 71