A person lent certain sum of money at 5% per annum simple interest and in 15 years the interest amounted to Rs 250 less than the sum lent. What was thesum lent (in Rs)?
Alarms from 3 different clocks sound after every 2, 4 and 6 hours, respectively. If the clocks are startedat the same 6 time, how many times do the alarms ring together in 3 days?