Question #64d1f

1 Answer
Sep 7, 2017

#14# years

Explanation:

If Sachin's age is represented by #s# and Rahul's is represented by #r#, then we can write the equations

#s=r-4#

#s/r = 7/9#

From the second equation, we can cross-multiply to get

#7r = 9s#

#r = (9s)/7#

Now, substitute this into the first equation and solve for #s#.

#s = (9s)/7 -4#

#s = (9s)/7 - 28/7#

#s = (9s - 28)/7#

#7s = 9s - 28#

#-2s = -28#

#s = 14#

Sachin is #14# years old.