90 (0.6)^t/11=30

Question

90 (0.6)^t/11=30

 

Round to the nearest integer

Answer 1

90 (0.6)^t/11=30   is the problem--you should say solve for t, rounding the answer to the nearest integer??

 

Dividing both sides by 90 and multiplying both sides by 11, you now have  0.6^t = 11/3

 

Taking logarithms, t•log 0.6 = log(11/3)  so  t = -2.5435

 

Check the answer !

 

As you see, ROUNDING THE ANSWER FOR SUCH A PROBLEM IS A VERY BAD IDEA.  Pass this message on to your instructor (using such a crude value won't check!)--and besides, this is the era of the calculator, which is NECESSARY to solve this problem, and it can be done very accurately unless you're commanded to make a crude (rounded) integer. Why sacrifice the great accuracy of a scientific calculator???