Mona has invested $2840 in a savings account for 6 years. she earned $894.60 in a simple interest. what was the annual interest rate?

The annual interest rate was 5.25%.

Step-by-step explanation:

Simple interest can be calculated using the following formula:  I = PRT, where I=simple interest, P=principal amount, R=percentage rate and T=time.  In this problem, Mona started with a principal amount of $2840, or P=2840 and invested for 6 years, or T=6, to gain simple interest in the amount of $894.60, or I=894.60.  When we put in the values for our variables in the equation, we get:  894.60 = (2840)(6)R.  Multiplying 2840 x 6 = 17040 and gives us:  894.60 = 17040R.  Using inverse operations to isolate the variable, we divide both sides by 17040 to get R=0.0525.  Since the rate is a percentage, we need to multiply our answer by 100 to get 5.25%.  

there are 70 more legs than eyes at the dog show (196 – 126 = 70). dogs have two more legs than eyes, and humans have the same number of legs as eyes. thus 70 is twice the number of dogs at the show, so the number of dogs is half of 70, which is 35. to get the number of humans, subtract 35 from 63: 63 – 35 = 28.

step-by-step explanation: