+0  
 
-1
285
2
avatar+171 

Assume \(0 < r < 3\). Below are five equations for \(x\). Which equation has the largest solution \(x\)?

 

\(\textbf{(A)}\ 3(1 + r)^x = 7\qquad \textbf{(B)}\ 3(1 + r/10)^x = 7\qquad \textbf{(C)}\ 3(1 + 2r)^x = 7 \textbf{(D)}\ 3(1 + \sqrt {r})^x = 7\qquad \textbf{(E)}\ 3(1 + 1/r)^x = 7\)

 

 Jul 30, 2019
edited by FlyEaglesFly  Jul 30, 2019
 #1
avatar+30288 
+1

Since the numbers in brackets are all greater than 1 for 0 < r < 3, the smallest value of the bracketed term will require the largest value of x.

 

The smallest is (1 + r/10), so (B) will require the largest x.

 Jul 30, 2019
edited by Alan  Jul 30, 2019
edited by Alan  Jul 30, 2019
 #2
avatar+171 
-1

I put all five now

 Jul 30, 2019

10 Online Users