I do not believe that either possible strengthener actually strengthens the argument. I would eliminate those answer choices almost immediately. For #1, the fact there is more than one student in the class never connects in any way to the idea of being intelligent. Since the possible answer has noth...

This is a simultaneous equations question demonstrating the common trap of showing two equations that are not distinct and thus not solvable for the individual variables. It doesn't matter who buys the pizzas - the prices of the pizzas are all we care about. Given: V = price of a veggie pizza. M = p...

To add a bit to this smart approach by GMATGuruNY, why choose 9 as the divisor to check? Because it's very easy to tell when a number is a multiple of 9. If the sum of the digits of the number is 9 or a multiple of 9, then the number itself is a multiple of 9. So after eliminating A because it's eve...

It's often easy to do any question of this type by using real numbers. For this question, imagine that it takes 21 gallons to fill the pool. (I specifically chose a multiple of 3.5 and 3 to make the math simple.) So Pool = 21 gallons. Next, break down each person/machine/pipe rate into a number of g...

Sure. All you need to understand is that the number is negative and it's a fraction between 0 and 1. There are rules. Square a negative number and the result is a positive number so b and d will both be positive while a and c are negative. (Even exponents always result in positive numbers). So with ...

Alternatively, you could just use the answer choices to solve this problem. Let's start in the middle, with answer choice C: If the "shorter" side is 34 feet, the "longer" side would have to be 6 feet in order to make the perimeter equal to 80 [(2 x longer side) + (2 x shorter si...

A different (and quite easy) strategic approach to solving this problem without getting into square roots, the distance formula, or the Pythagorean theorem is to create a rectangle and subtract the areas of the right triangles not contained in the triangle you're looking for. Specifically, make poin...

The key to this problem is to use the formula: Distance = Rate x Time. Step 1: Find the total distance the rocket has traveled. Part I: Rocket goes up: The rocket soars for 12 seconds (time) at 150 meters per second (rate). D = R x T D = 150 m/s x 12 s D = 1800 meters Part II: Rocket comes down: Dis...