Question

If the present ages of two brothers are in the ratio of 5:7 and sum of their ages after 15 years is 51 years

Answer 1

Sum of the present age=51-15=36

So,5x+7x=36

12x=36 or x=3

So ages are 5x=5×3=15years

7x=7×3=21 years

Answer 2

Answer:

Ages of two brothers are 8 years 9 months, 12 years 3 months

Step-by-step explanation:

The given problem might be about finding ratios of two brothers

Given that ratio of the age of two brothers = 5 : 7  

sum of their ages after 15 years = 51 years            

from given ratio let 5x and 7x are be the ages of two brothers  

After 15 years ages will be  5x+15,  7x+15

from given data sum of the ages after 15 years = 51 years    

                 ⇒ 5x+15+7x+15  = 51

                 ⇒ 12x + 30 = 51

                 ⇒  12x = 51 - 30

                 ⇒  12x = 21

                 ⇒ 4x = 7      

                 ⇒ x = $\frac{7}{4}$  

ages of two brothers ⇒   5x =$5(\frac{7}{4})$ = $\frac{35}{4}$ = $8\frac{3}{4}$ = 8 years 9 months

                                   ⇒  7x = $7(\frac{7}{4} )$ = $\frac{49}{4}$ = $12\frac{1}{4}$ = 12 years 3 months