Sunday, April 20, 2008

Another Taxi Story

In the Twin Cities, taxi fare works like this: as soon as the passenger gets in, the driver drops the flag and $2.50 appears on the meter. Every mile, including the first mile, costs an additional $1.90. Fractions of a mile are 38 cents for every 1/5 of a mile.

My car wouldn't start and I needed to take an urgent trip. Using Mapquest, I found the trip was 15.6 miles long. What was the likely fare, including a 20% tip? Round the fare plus tip to the nearest dime (10 cents).

I found out in advance that the taxi company accepts credit cards. But, if not, could I have paid with $40 in cash?

--------------------------------
Answer: XXXVIII dollars and LX cents. I could have paid with two twenty-dollar bills.

Note: V=5, X=10, and L=50.

Wednesday, November 7, 2007

Voting for school taxes

The school district I live in just had a vote to increase taxes to pay for better schools.

Before I get to that, consider a simple example. Suppose 20 people vote yes and 30 people vote no.

What were the respective percentages? You need to get the total first! In total, 20 plus 30, or 50 people, voted. The percentages were 40% "yes" and 60% "no."

In real life, 4702 people voted "yes" to increase taxes and 3554 people voted "no" to the tax increase. What were the percentages of yes and no votes?

There was a second question on the ballot, to increase taxes more to cover improvements in education and cover inflation. To this, 4092 voted "yes" and 4150 voted "no." What were the percentages of yes and no votes?

Was the vote on the second question close? Did the same total number of people vote on both questions?

Hint: this is a favorite question on standardized tests. The test doesn't tell you to, but you must add the votes to get the total first (!) then calculate the percentages.