Two numbers are in the ratio 2 : 3. If 4 is subtracted from the first number, the ratio becomes 1 : 2. What are the numbers?
A
14, 21
B
16, 24
C
18, 27
D
20, 30
উত্তরের বিবরণ
Solution:
Let the two numbers be: 2x and 3x
According to the question,
(2x - 4)/3x = 1/2
⇒ 2(2x - 4) = 3x
⇒ 4x - 8 = 3x
⇒ x = 8
∴ First number = 2 × 8 = 16
∴ Second number = 3 × 8 = 24
0
Updated: 2 months ago
The present ages of A and B are in the ratio 3 : 5. After 10 years, the ratio of their ages will be 4 : 6. What is the difference in their present ages?
Created: 1 week ago
A
14 years
B
18 years
C
25 years
D
20 years
Question: The present ages of A and B are in the ratio 3 : 5. After 10 years, the ratio of their ages will be 4 : 6. What is the difference in their present ages?
Solution:
Let the present ages be,
A = 3x and B = 5x
Ages after 10 years,
A = 3x + 10
B = 5x + 10
According to the problem, the ratio becomes 4 : 6
(3x + 10) : (5x + 10) = 4 : 6
⇒ (3x + 10)/(5x + 10) = 4/6
⇒ 3(3x + 10) =2(5x + 10)
⇒ 9x + 30 = 10x + 20
⇒ 10x - 9x = 30 - 20
∴ x = 10
A = 3 × 10 = 30 years
B = 5 × 10 = 50 years
∴ Difference = 50 - 30 = 20 years
0
Updated: 1 week ago
In a business, the ratio of the capitals of A and B is 2 : 1, that of B and C is 4 : 3 and that of D and C is 6 : 5. What is the ratio of the capitals of A and D?
Created: 2 months ago
A
5 : 9
B
12 : 17
C
11 : 15
D
20 : 9
Solution:
Given,
A : B = 2 : 1 ⇒ A/B = 2/1
B : C = 4 : 3 ⇒ B/C = 4/3
D : C = 6 : 5 ⇒ C/D = 5/6
Now, A/D = (A/B) × (B/C) × (C/D)
= (2/1) × (4/3) × (5/6)
= 20/9
∴ A/D = 20 : 9
0
Updated: 2 months ago
Three numbers are in the ratio 2 : 3 : 5, and their H.C.F. is 15. What is their L.C.M.?
Created: 2 months ago
A
450
B
600
C
300
D
475
Question: Three numbers are in the ratio 2 : 3 : 5, and their H.C.F. is 15. What is their L.C.M.?
Solution:
দেওয়া আছে,
সংখ্যা তিনটির গ. সা. গু ১৫
সংখ্যা তিনটি হচ্ছে (২ × ১৫) বা ৩০, (৩ × ১৫) বা ৪৫, (৫ × ১৫) বা ৭৫
এখন,
৩০, ৪৫, ৭৫ এর ল. সা. গু = ৪৫০
0
Updated: 2 months ago
