What should come next in the following letter series?

         PQRSTABCDEPQRSABCDEPQRSABCDPQ

The ratio of the speeds of a car, a train and a bus is 5:9:4. The average speed of the car, the bus and the train is 72km/hr together. What is the average speed of the car and the train together?

There are some parrots and some tigers in a forest. If the total number of animal heads in the forest is 858 and the total number of animal legs is 1,846 what is the number of parrots in the forest?

Kiran purchased a car for Rs 2,50,000 and sold it for Rs 3,48,000. What is the percent profit he made on the car?

The difference between a two-digit number and the number obtained by interchanging the two digits of the number is 9. If the sum of the two digits of the number is 15, then what is the original number?

The present ages of Amit and his father are in the ratio of 2:5 respectively. Four years hence the ratio of their ages will become 5:11 respectively. What was the father’s age five years ago?

In the following number series only one number is wrong. Find out the wrong number?

     5     55     495     3465     17325     34650     51975

In the following number series only one number is wrong. Find out the wrong number?

       2     9     32     105     436     2195     13182

The total marks obtained by a student in physics, chemistry and maths together is 120 more than the marks obtained by him in chemistry. What is the average marks obtained by him in physics and maths together?

An amount of money is to be divided among P, Q and R in the ratio of 3:5:7 respectively. If the amount received by R is Rs 4,000 more than the amount received by Q, what will be the total amount received by P and Q together?

    384     381     372     345     264     ?