• # question_answer The sum of the present ages of father and son is 90 years. 10 years earlier the ratio of their ages was 5: 2. The present age of the father is: A)  65                    B)  68 C)  70                    D)  60

[d] Let present age of father=x Present age of son=y According to question, $x+y=90\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,...(i)$                  ? (i) Now, $\frac{x-\,10}{y-\,10}=\frac{5}{2}$ $2x-\,20=5y-\,50$ $2x-\,5y=-\,30\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,...(ii)$                      ? (ii) From eq. (i) and (ii) x=60 y=30 $\therefore$The present age of mother = 60 years.