Challenge Answers
Question:
James is currently 2/5 of his older brother's age and in two years he will be half of his older brother's age.
Two years ago, James was only 1/4 of the age of his older brother's age at the time.
How old is James' older brother?
Solution:
James is 4 and his brother is 10.
Original problem: http://mybrainteasers.com/age-problem/
9-7-15
Question:
You are on your way to visit your Grandma, who lives at the end of the valley. It's her birthday, and you want to give her the cakes you've made.
Between your house and her house, you have to cross 7 bridges, and as it goes in the land of make believe, there is a troll under every bridge! Each troll, quite rightly, insists that you pay a troll toll. Before you can cross their bridge, you have to give them half of the cakes you are carrying, but as they are kind trolls, they each give you back a single cake.
How many cakes do you have to leave home with to make sure that you arrive at Grandma's with exactly 2 cakes?
Solution:
2
(9-10-15)
Question:
Given only one of each letter in the alphabet, what are
the smallest and largest numbers that you could write down?
Answer:
Using only one of each letter in the alphabet, you can spell:
ZERO or NOUGHT
MINUS FORTY (allowing negative numbers)
FIVE THOUSAND
These are the smallest and largest possible numbers.
(9-20-15)
Question:
According to the traditional song, on the first day of Christmas (25th December), my true love sent to me:
. A partridge in a pear tree
On the second day of Christmas (26th December), my true love sent to me THREE presents:
. Two turtle doves
. A partridge in a pear tree
On the third day of Christmas (27th December and so on) my true love sent to me SIX presents:
. Three French hens
. Two turtle doves
. A partridge in a pear tree
This carries on until the the twelfth day of Christmas, when my true love sends me:
Twelve drummers drumming
Eleven pipers piping
Ten lords a-leaping
Nine ladies dancing
Eight maids a-milking
Seven swans a-swimming
Six geese a-laying
Five gold rings
Four calling birds
Three French hens
Two turtle doves
A partridge in a pear tree
After the twelve days of Christmas are over, how many presents has my true love sent me altogether?
Solution:
Day by Day:
1 + 3 + 6 + 10 + 15 + 21 + 28 + 36 + 45 + 55 + 66 + 78 = 364 presents
Which is really interesting when you think there are 365 days in a typical year!
A kind reader, Martin J. Fowler, found this interesting symmetry in the total number of each present:
12 Partridges (12 days x 1)
22 Turtle Doves (11 days x 2)
30 French Hens (10 days x 3)
36 Calling Birds (9 days x 4)
40 Gold Rings (8 days x 5)
42 Geese Laying (7 days x 6)
42 Swans swimming (6 days x 7)
40 Maids a Milking (5 days x 8)
36 Ladies dancing (4 days x 9)
30 Lords a Leaping (3 days x 10)
22 Pipers Piping (2 days x 11)
12 Drummers drumming (1 day x 12)
(9-26-15)
Problem:
Spaghetti is famous for the way it all gets tangled up on the plate. Those of you who think they know their alphabet are bound to get all tangled up with this puzzle too, unless you read it and think about it very carefully!
What letter of the alphabet is the one which comes eight letters before the letter which comes five letters after the fourth appearance of the first letter to occur four times in this sentence?
Solution:
"r"
You get this by working backwards through the puzzle: the first letter to occur four times is t: WhaT leTTer of T....
Five letters after the fourth "t" is the letter "p", and eight letters before that is "r".
(10-12-15)
Problem:
Hungry Horace was looking through the family photograph album, which has a photo of each of his parent, each of his grandparents, all the way up to each of his great-great-great-grandparents.
How many photos is that?
Solution:
2 parents
4 grandparents
8 great-grandparents
16 great-great-grandparents
32 great-great-great-grandparents
2 + 4 + 8 + 16 + 32 = 62 photos in all.
(10-17-15)