A certain sum of money at simple interest amounts to ₹1,512 in 3 years and to ₹1,668 in 4.5 years. The rate of interest on this sum of money is:
\( \frac{26}{3} \) %
\( \frac{24}{3} \) %
\( \frac{28}{3} \) %
10%
A father can complete a task in 8 days, while the son can do it in 7 days. If they work on alternate days, with the father starting, then in how many days will the task be completed?
Two integers are selected at random from the first 11 natural numbers. If the sum of the integers is even, then the probability that both the numbers are odd is:
\( \frac{13}{121} \)
\( \frac{3}{5} \)
\( \frac{4}{9} \)
\( \frac{5}{11} \)