Medium Mathematical Puzzles - 2

Mathematical riddles are commonly asked in aptitude tests and other competitive exams. These are based on various concepts of number system, algebra, clocks, probability, etc. Here is a compilation of variety of math riddles in the order of difficulty - easy, medium and difficult. Each article consists of 10 maths number puzzles with answers and explanations. Solve these medium-level maths puzzle questions and check your level of preparation:
Q.1. Santa was copying down his Mathematics Homework the other day, but because he was in a hurry he copied it down incorrectly. They had been learning about multiplication and had five of them to do at home.Santa, however, copied every number down backwards:
Instead of writing 14 x 82, Santa wrote 41 x 28
Instead of writing 13 x 62, Santa wrote 31 x 26
Fortunately for Santa all his answers were still correct!
What were the other three questions?
Q.2. There are 17 beads in a necklace with the largest and most valuable in the middle.
Starting from one end, each successive beads  is worth Rs.100 more than the one before (up to the middle one), but starting from the other end each beads  is worth Rs.50 more than the one before, up to the big bead. The whole necklace is worth Rs.15,000. What is the value of the middle pearl?
Q.3. At 8 AM, a clock ticks 8 times. The time between first and last ticks is 35 seconds. How long does it tick at 11 Noon?
Q.4. A truck driver, once in a week, leaves his house and drives to the river dock to pick up supplies. At 6:05 PM, one-fifth of the way to the dock, he passes the Temple. At 6:15 PM, one-third of the way, he passes the Amritsari Dhaba. At what time does he reached the dock?
Q.5. Sami decided to give Kachoris to her friends on her Birthday. If she gives 3 Kachoris to each friend, one friend will get only 1 Kachoris. Also, if she gives 2 Kachoris to each friends, she will be left with 13 Kachoris. How many Kachoris Sami got on her Birthday? And how many friends are there?
Q.6. In the equation shown, P, Q, R, S, and T are 5 consecutive positive integers. What are they?
P2 + Q2  + R2 = S2 + T2
Q.7. Neeti puts into the basket one banana when ordered ‘one’, one kiwi  when ordered ‘Two’, one litchi when ordered ‘Three’, and is asked to take out from the basket one banana and kiwi when asked Four.
A sequence of order is given as: 12342231124124213
How many total fruits will be in the basket at the end of the above order sequence?
A. 9
B. 8
C. 11
D. 10
Q.8. 3 shots can be fired from an air gun at a time. If the probabilities of the first, second and the last shot hitting the enemy helicopter are 0.6, 0.5 and 0.4, what is the probability that three shots aimed at the enemy helicopter will bring the helicopter down?
Q.9. The price of a commodity increases by 25% every odd year and reduces by 20% every even year. By how much percentage, the prices would have risen or fallen after exactly 8 years?
Q.10. Find the next 2 numbers in the series: 1, 8, 11, 69, 88, 96, 101, 111, 181, ...