How to Save Gas

If you could chose to increase the average fuel economy of a car, which of these would save the most fuel?

1. 10mpg -> 12mpg
2. 12mpg -> 15mpg
3. 15mpg -> 20mpg
4. 20mpg -> 30mpg
5. 30mpg -> 60mpg

It turns out they all save the same amount of fuel.

If you travel 100 miles:

100 / 10 = 10 gallons used
100 / 12 = 8 1/3 gallons used

10 – 8 1/3 = 1 2/3 gallons saved

100 / 30 = 3 1/3 gallons used
100 / 60 = 1 2/3 gallons used

3 1/3 – 1 2/3 = 1 2/3 gallons saved

Posted in Brain Teasers

A Dog Running in the Forest

How far can a dog run into the forest?

Halfway. After that it will be running out of the forest.

Posted in Brain Teasers

Pleased With Their Death

Beulah died in the Appalachians while Craig died at sea. Everyone was much happier with Craig’s death. Why?

Beulah and Craig were hurricanes.

Posted in Brain Teasers

Little Cat’s Feet

It comes in on little cat’s feet,
Is neither sour, nor sweet.
Hovers in the air,
And then is not there.

Fog or mist

Posted in Riddles

A Red Robe and Staff In Hand

I wear a red robe,
With staff in hand,
And a stone in my throat.
Cut me and I weep red tears

What am I?

A cherry

There are a few other variations of this one:

As I went through the garden gap,
Who should I meet but Dick Red-cap!
A stick in his hand, a stone in his throat,
If you’ll tell me this riddle, I’ll give you a groat.
(Said to be the lyrics to A Cherry)

I slipped down a slippery gap,
Found a man with a red cap,
He had a stick in his back and a stone in his belly,
Riddle me this and I’ll give you a penny.

Posted in Riddles

Cat-Related Phrases

What are these words or phrases, which contain the word cat?

A dreadful event (11 letters)
A robber who climbs walls (10 letters, 2 words)
A systematic list (7 letters)

Catastrophe
Cat Burglar
Catalog

Posted in Brain Teasers

Three Brothers Share A Family Sport

Three brothers share a family sport:
A non-stop marathon
The oldest one is fat and short
And trudges slowly on
The middle brother’s tall and slim
And keeps a steady pace
The youngest runs just like the wind,
A-speeding through the race
“He’s young in years, we let him run,”
The other brothers say
“‘Cause though he’s surely number one,
He’s second, in a way.”

The hands on a clock (hour, minute, second).

Posted in Riddles

How Old is Malcolm, His Dad and Grandfather?

Malcolm is the number of weeks of his father’s age treated as days and his grandfather’s age in months. All three of their ages add up to 120 years. How old is Malcolm, his father and his grandfather?

Malcolm is 6.
The father is 42. 42 days = 6 weeks.
The grandfather is 72. 72 months = 6 years.

Posted in Brain Teasers

A Word of Weather

Find this eight-letter word.

The first four letters are a variation of the weather.
The third through seventh letters give support but also could used when someone is executed.
And the last three letters forms the name of a person.

What’s the word?

Mistaken.

Mist = Variation of weather.
Stake = a tent stake or when someone is burned at the stake.
Ken = a person’s name.

Posted in Riddles

False Positive HIV Test

Imagine an HIV test that is 95% accurate (false positive rate of 5%) and around 2% of the tested population is infected with HIV. What is the probability that you actually have HIV when your test comes back positive?

29%

To read more about this, see the False Positive Paradox page on Wikipedia.

Posted in Brain Teasers