Answer Choices
Each successive year, 2% of the initial savings is added to the value of the account.
Each successive year, 1.5% of the initial savings and $100 is added to the value of the account.
Each successive year, 1% of the current value is added to the value of the account.
Each successive year, $100 is added to the value of the account.
Explanation for Question 21 From the Math (Calc) Section on the Official Sat Practice Test 3
Not for question 21. We're told that of the following four types of saving 2 account plans, which option would yield exponential growth of the money in 3 the account. All right. So the best way to go about this question is 4 just to read each answer choice and also think about what exponential growth is, 5 right? Exponential growth on the grass looks, 6 something like this. It gets bigger over time. 7 Whereas the linear growth stays going up by the same amount over time. 8 Um, and now if we look at a, it says that each success of 9 year 2% of the initial savings is added to the value of the account. 10 And so you might see 2%. You're like, okay, I'm going up by 2%. 11 That doesn't sound linear, but it says 2% of the initial savings, 12 right? So say your initial savings was a hundred dollars. 13 2% of a hundred dollars is two. 14 And so that means that each year you're going up by $2, 15 which is the same amount, which is actually a linear description. 16 So that 2% is misleading because it's 2% of a non changing value. 17 So you're going up by a non changing value as well. 18 Now B says 1.5% of the initial savings and a hundred dollars. 19 This is the same thing, right? Let's say the initial savings was still 100, 20 1.5 of 100 is a dollar and a half, 21 right? And then we're still adding a hundred dollars. 22 So you're just going up by $101 and 50 cents. 23 Still that number doesn't change. It's always going to be 101.5. 24 And if that number doesn't change, then B describe...