Question

3. The ratio of the present ages of two brothers is 4: 5. After 10 years, the ratio or their ages would be 6 7. Find the age of the elder brother after 15 years. (1) 35 years (2) 40 years (3) 50 years (4) 25 years​

Answer 1

Answer:

the age of the elder brother after 15 years is 35

Step-by-step explanation:

Given The ratio of the present ages of two brothers is 4: 5

Let the age be 4x : 5x

After 10 years, the ratio or their ages would be 6 : 7

4x+10 : 5x+10  = 6 : 7

$\frac{4x+10}{5x+10} = \frac{6}{7}$

7(4x+10) = 6(5x+10)

28x + 70 = 30x + 60

30x - 28x = 70 - 60

2x = 10

x = 5

Present age are 20 & 25

the age of the elder brother after 15 years is 20 + 15 = 35