y isn't the year he became a doctor, but rather the number of years he was a doctor.

If he became a doctor 10 years earlier, then the number of years as a doctor increases by 10 => y + 10

I get B) 4.

Basically, you use the fact that the arc length is 1/6 the circumference to determine that the angle of the arc is 60 and use 30-60-90 triangle properties.

A picture is worth a thousand words so...

From my experience and what I have read: Easy Problems require 1 step. Medium Problems require either 2 steps or 1 step and a trick/trap. Hard problems require either 3 steps or 2 steps and a trick/trap w/ sometimes more than 1 trick/trap. A lot of times you have to see one of the tricks/traps befor...

Let x = the distance between A and B.

Day 1: Traveled x/3 | Remaining = (2/3)x
Day 2: Traveled (2/5)(2/3)x = (4/15)x | Remaining = x - x/3 + (4/15)x => x - (5/15)x + (4/15)x = (15/15)x - (9/15)x = (6/15)x
Day 3: Traveled 144

Use this to solve for x: 144 = (6/15)x => x =360

Day 1: 360/3 = 120

Important items from the stem: 2, 5, and minutes (1) Think of the SW as not moving and the truck is 2 miles ahead of it. Subtract the SW speed from the truck's speed..70-65 = 5. So, think of the truck as going 5 mph. How long will it take the truck to go 3 miles? d = rt => 3 = 5t => t = 3/5 hours =>...

http://www.beatthegmat.com/counting-per ... t6207.html

15 coins, 6 nickels, 9 not nickels

Prob of first pick not a nickel = 9/15
Prob of second not being a nick = 8/14

(9/15)*(8/14) = 72/210 = 24/70 = 12/35