Free GMAT Prep Hour: Data & Data Sufficiency

[@deveshraj8383]

Very well explained ! thanks a lot for making these available on KZbin :)

[@ajitrajendran63]

Are quant DS of the past basically the same as the DS under the data insight section? Thanks

[@Voivod74]

Thank you for this! These videos should have many more views and comments!!

[@manhattanprepgmat6791]

You're so very welcome! We're glad you're finding them helpful. :)

[@manhattanprepgmat6791]

Just a note - I spotted an error that I made at 56:25, and while it doesn't change the answer to the question, I want to make sure to fix it! The correct expression should be that k2 = k3 = k1 + 12,500 (not minus because they earned MORE than the oldest child). Therefore, the correct equation at 57:15 should be k1 = k3 + 12,500. That only changes the sign in the final equation: 2100 = (k3 + 62.5) + (k3 - 12.5) + k3 + k3.

[@Mister.Unknown]

Am I the only one who doesn't quite get how Solution 5 can be done with the second statement by itself?

[@manhattanprepgmat6791]

Hi! Let me know if there is a specific point in the solution where the steps get confusing, but it can help to think about the information in the question stem (200,000 = S + k1 + k2 + k3) as an equation with 4 variables. You definitely can't solve this for any one of the variables individually - you technically need 4 equations to solve for 4 variables. However, statement 2 gives you 3 more equations: (1) the two youngest children get the same amount of money (k2 = k3), (2) the oldest child receives 12,500 less than either of them (k1 = k2 = k3 - 12,500), and the spouse receives $62,500 more than either of them (S = k3 + 62,000). With these 3 new equations (combined with the equation in the stem), you can replace S, k1, and k2 in the original equation to get a single equation in terms of k3: 200,000 = (k3+62,000) + (k3-12,500) + k3 + k3. You can therefore solve this equation for k3. Also, thank you for pointing this out as I spotted a small mistake in one of our signs!