Most of the Value DS questions based on Mean, Median, Mode, and Range intrigues the students in an unusual way. However, following a
basic approach and some
visual inspection can make work a lot easier.
Let's start by writing down what we know from the question and what the question is asking to find out (Yes, it is important to put down the info on the scratch paper. You can not keep everything in your head and assume that you will be as cool in the last set of questions as you were in the initial set of questions).Know: Range of Female = 30 Range of All students = ?
Range of Male = 40
Now, think of what we need to get the answer. We need the smallest and the largest height (from the data of all students).
1) Av Male = Av Female + 10 This will not provide us the largest and smallest value. So,
insufficient.
2) Shortest Female = Shortest Male - 15 Don't jump on the solution. That's a bad strategy. Writing equations can be one way. But that makes it complicated to comprehend. Let's use number line. It will help improve visual inspection.
You must use superscripts and subscripts while doing these kind of questions. Since, it is not possible here, I'll use following terminology and will show you step by step addition of information on the diagram, so that it is easier for you to understand:
SF = Shortest Female
SM = Shortest Male
TF = Tallest Female
TM = Tallest Male
|-----15-----|
|_________|________________________
SF SM
|----------30--------|
|---15---|-----15---|
|_______|________|________________
SF SM TF
|------------40---------|
|----------30--------|
|---15---|-----15---|
|_______|________|__________|______
SF SM TF TM
|--------------40--------|
|----------30--------|
|---15---|-----15---||------10-----|
|_______|________|__________|______
SF SM TF TM
|------------------55-----------------|
So, the range is 55. Thus, Statement 2 is
sufficient.
So, the answer is B. Sorry for the distorted diagrams. This is the best I can do in typing on this forum. :/Note: the bar for 40 is starting from SM and ends on TM.
Give kudos if you liked the solution. Deepti Singh
Master Trainer - GMAT
Manya - The Princeton Review