Request you to help me with the solution for the following, why would the interest be 1.1 here?
If 35% of the acreage of a national forest was destroyed in a wild fire, and the remainder regenerates at a rate of 10% a year, after how many years , assuming no further losses , will the forest exceeds its original acreage ?
(A) 10 (B) 8 (C) 5 (D) 4 (E) 3
5-Day Free Trial
5-day free, full-access trial TTP
Available with Beat the GMAT members only code
MORE DETAILS
question on percent
This topic has expert replies
-
[email protected]
- Newbie | Next Rank: 10 Posts
- Posts: 8
- Joined: Thu Dec 24, 2015 6:13 am
GMAT/MBA Expert
-
[email protected]
- Elite Legendary Member
- Posts: 10392
- Joined: Sun Jun 23, 2013 6:38 pm
- Location: Palo Alto, CA
- Thanked: 2867 times
- Followed by:511 members
- GMAT Score:800
Hi sucheta.lahiri,
This question can be solved in a couple of different ways. Here's how you can TEST VALUES to get to the correct answer.
Let's start with 100 acres.
We're told that 35% of the acres were destroyed in a fire...
100 - (.35)(100) = 65 acres left
Then the remainder grows at 10% a year. We're asked how long it takes to get above 100 acres....
Year 1 = 65 + (.1)(65) = 71.5 acres
Year 2 = 71.5 + (.1)(71.5) = 78.65 acres
Year 3 = 78.65 + (.1)(78.65) = about 86.5 acres
Year 4 = 86.5 + (.1)(86.5) = about 95 acres
Year 5 = 95 + (.1)(95) = about 104.5 acres
Thus, it takes 5 years to exceed the original 100 acres.
Final Answer: C
GMAT assassins aren't born, they're made,
Rich
This question can be solved in a couple of different ways. Here's how you can TEST VALUES to get to the correct answer.
Let's start with 100 acres.
We're told that 35% of the acres were destroyed in a fire...
100 - (.35)(100) = 65 acres left
Then the remainder grows at 10% a year. We're asked how long it takes to get above 100 acres....
Year 1 = 65 + (.1)(65) = 71.5 acres
Year 2 = 71.5 + (.1)(71.5) = 78.65 acres
Year 3 = 78.65 + (.1)(78.65) = about 86.5 acres
Year 4 = 86.5 + (.1)(86.5) = about 95 acres
Year 5 = 95 + (.1)(95) = about 104.5 acres
Thus, it takes 5 years to exceed the original 100 acres.
Final Answer: C
GMAT assassins aren't born, they're made,
Rich
