Sachin is younger than Rahul by 7 years. If their ages are in the respective ratio of 7:9, how old is Sachin?A. 16 yearsB. 18 yearsC. 28 yearsD. 24.5 yearsE. none of these

Assume the age of Sachin as ‘x’. Thus get the age of Rahul and form of relation connecting their present ages to 7:9. Use cross product property and find the value of x. Complete step-by-step answer: Let us assume the age of Sachin as ‘x’. It is said that Rahul is 7 years older than Sachin. Therefore the age of Rahul is (x + 7). Now the ages of Sachin and Rahul are given in the ratio 7:9. Thus we can say that x:x+7=7:9 . Thus we can say that x:x+7=7:9 . We can also write it as, xx+7=79 . Now using cross product we can write that, 9x=7(x+7)9x=7x+49 Now let us rearrange them and find the value of x. 2x=49x=492=24.5 Thus the age of Sachin = x = 24.5 Age of Rahul = x + 7 = 24.5 +7 = 31.5 What we need is the age of Sachin which is 24.5 Thus we got the age of Sachin as 24.5 years. Option D is the correct answer. Note:We can take the age of Rahul as ‘x’ and that of Sachin as x-7. Thus the ratio becomes, x−7:x=7:9 , which can also be written as, x−7x=79⇒9(x−7)=7x9x−63=7x∴x=63/2=31.5 Thus the age of Rahul = x = 31.5 years. Age of Sachin = x – 7 = 31.5 – 7 = 24.5 years.