Math riddles

mathshort

How many times do a clock's hands overlap

How many times do a clock's hands overlap in a day ?
22 times. am 12:00 1:05 2:11 3:16 4:22 5:27 6:33 7:38 8:44 9:49 10:55 pm 12:00 1:05 2:11 3:16 4:22 5:27 6:33 7:38 8:44 9:49 10:55
93.55 %
39 votes

logicmathshort

Magic number

Ramanujan discovered 1729 as a magic number. Why 1729 is a magic number ?
It can be expressed as the sum of the cubes of two different sets of numbers. 10^3 + 9^3 = 1729 and 12^3 + 1^3 = 1729
90.47 %
44 votes

cleanmathshort

2 numbers

Divide 110 into two parts so that one will be 150 percent of the other. What are the 2 numbers?
44 and 66.
93.39 %
38 votes

logicmathshort

10 + 4 = 2

Can you make 10 plus 4 = 2?
Yes. 10 o'clock + 4 hours = 2 o'clock.
89.58 %
40 votes

logicmath

Three daughters

Sam has got three daughters. The eldest daughter is the most honest girl in the universe and she always speaks truth. The middle daughter is a modest woman. She speaks truth and lies according to the situations. The youngest one never speaks truth. Not a single word she spoke was true and would never be true. Sam brought a marriage proposal for one of his girls. It was John. John wanted to marry either the eldest or the youngest daughter of Sam as he can easily identify whether the girl speaks truth or lie! John told his desire to Sam. However, Sam laid a condition. He told John that he will not say who the eldest, middle or youngest one is. Also, he allowed john to ask only one question to identify the eldest or youngest so he can marry one. John asked one question and found the right girl. What was the question and whom should he pick? He asks this question to one of the daughters. If he asked this question to older daughter pointing at other two, he probably would know the youngest one! NO matter, she always speaks truth. If he asked the question to middle one, probably he can choose either. If he asked the youngest one, she always lies and he can find eldest one! No matter, he has to choose the youngest one based on the answer.
The question he asked is, ‘Is she older than her!’ He asks this question to one of the daughters. If he asked this question to older daughter pointing at other two, he probably would know the youngest one! NO matter, she always speaks truth. If he asked the question to middle one, probably he can choose either. If he asked the youngest one, she always lies and he can find eldest one. No matter, he has to choose the youngest one based on the answer.
93.39 %
38 votes

logicmathshort

100

Can you arrange four 9's and use of atmost 2 math symbols, make the total be 100?
99 / .99
93.22 %
37 votes

logicmathshort

Box full of marbles

There is a box full of marbles, all but two are blue, all but two are green, and all but two are red. How many marbles are in the box ?
There are 3 marbles (1 blue, 1 green, and 1 red).
93.05 %
36 votes