A1. 1973, 1979, 1987, 1993, 1997, 1999

A2. Here are four solutions. But with patience and pencil work, you can find more ..

A3. One of the fathers is the son of the other father. The problem posed would seem as if there are four persons involved. But that is not so. The three persons are grandfather, father and son.

A4. SX: Each square contains the first and last letters of the numbers one to nine positioned in such a way so as to form a magic square where each horizontal, vertical and corner-to-corner line totals 15.

A5. 98 - 76 + 54 + 3 + 21 = 100

A6. Sadhuna, Thursday. Suhaina, Wednesday . The names appear in alphabetical order, as do the days of the week.

A7. 73. It is spelt with 12 letters. The previous number is spelt with 11 letters and so on..

A8. 1. Wave, 2. Limerick , 3. Zone, 4. Dough , 5. Joy, 6. Pyre , 7. Zebra , 8. Qualify , 9. Exist

A9. (150 - 1) = 149 , since all but one, lose one game.

A10.

• Abort (It is five letters long)
• Act (Last letter cannot be placed first to form another word)
• Agt (Not an actual word)
• Arc (Does not end with 'T')
• Opt (Does not start with 'A')
• Apt (Not in alphabetical order with the rest)

A11. ( E) The preceeding letters are the vowels extracted from the question!

A12. The grid should contain 1x1, 2x2, 3x3, 4x4, 5x5, 6x6, 7x7 and 8x8. The missing numbers are, therefore, 5,6,8,8 and all the numbers are placed in the grid so that the same number is never horizontally or vertically adjacent.

A13. At some time during the calculation you will be multiplying by (x-x), which equals 0, therefore the product will be 0.

A14. 11¹¹

A15. 17 (seventeen) - All numbers containing only 'E' vowels<

A16. 9 below, 10 above . Numbers appearing above the line are spelt with three letters only.

A17. 48 times.

A18. Nil. If three are correct then four must be.

A19. 

A20. MAID. All words can be prefixed with BAR to form another word.

A21. They each contain three adjacent consecutive letters of the alphabet, e.g. studio

A22. 857, 859 . Re-arrange the digits of 7731 in every possible way and then divide the resultant number by 9.

A23.

1. 529, 841 . They are the squares of progressive prime numbers.
2. 10 i.e. 9 x 7 x 3 x 7 x 6 = 7938. 7 x 9 x 3 x 8 = 1512. 1 x 5 x 1 x 2 = 100.
3. 3125 . i.e. 5⁵. The sequence is 1¹, 2², 3³, 4⁴, 5⁵

A24. Above the line . Straight letters go above; curved letters below.

A25.

1. IOE . They are the vowels extracted from the colours of the rainbow - red, orange, yellow, green, blue, indigo, violet.
2. AUA . They are the vowels extracted from the days of the week - Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday

A26. T. They are initials of odd numbers; one, three, five, etc.

A27.

1. P . The initial of the planets in order from the sun. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto.
2. X . A list of letters in the alphabet which are also Roman numerals.
3. S . The initials of the seven deadly sins: Pride, Wrath, Envy, Lust, Gluttony, Avarice, Sloth.

A28.

Lines Across: India, Peru, Turkey, Kenya, Malta, Nigeria, Italy, Japan, Spain, Cyprus
Lines Down : Mali, Panama, Fiji, Niger, Iran, Cuba, Burma, Canada, Haiti, Togo

A29.

1. If your answer is first, then you're wrong. You overtook the second runner and took their place, therefore you come second.
2. If you answered second-last, once again you're completely wrong. Think about it... How can you overtake the person coming last? If you're behind them then they can't be last. The answer is impossible!!

A30. NAME