# Brain Teasers 10 [With Answers]

Puzzle 1: Insert the missing alphabets to complete the series.

T, F, S, E, T, T, F, _, _, _, _, T, T, T, T

Answer: S, E, T, T

Explanation: The first “T” stands for Two. Now go on adding 2 to the series and take the first letter: Four, Six, Eight, Ten, Twelve, Fourteen. This way, we will get Sixteen, Eighteen, Twenty, Twenty-two or S, E, T, T.

Puzzle 2: If you are supposed to take pills at half an hour intervals, how many minutes would 5 pills last?

Answer: 120 minutes or 2 hrs. 5 pills can be taken over 4 half an hour intervals. Hence 4 x 30 = 120 mins.

Puzzle 3: In a class test Tony scored 160 marks in Geography and History together. If one third of his marks in Geography equals to half of the marks he scored in History, then how much has he scored in History?

Answer: 64

Explanation: Let the marks in Geography be G and History be H.

Eq 1: G + H = 160

Eq 2: G/3 = H/2

By the problem:

G = 160 – H

Therefore, putting the value of G in Eq 2:

(160 – H)/3 = H/2

Or, 320 – 2H = 3H

Or, 3H + 2H = 320

Or, 5H = 320

Or, H = 64

Puzzle 4: Turn IX into 6 without lifting your pen.

Answer: Write S in front of IX to make it SIX.

Puzzle 5: Cut a circular cake into 7 pieces with 3 cuts.

Answer: