Look at 36/3 = 12.
So let's try 12 along with the one before it and the one after it.
10 + 12 + 14 = 36
yay !
<u>Answer:</u>

<u>Solution:</u>
Given: x=30
To solve: 
On substituting the value of x,

On dividing 30 and 5 we get,

So, the option is 15.
This is a conversion problem. We know that 1 mile is 5280 feet, right? Since Ellie lives 2 miles, and two is double of 1, we just take 5280 and multiply that by two (or add it twice) to find how many feet is between Ellie's house and school. 5280 x 2 = 10560 (you get the same answer if you add 5280 twice). Therefore, 10560 feet lies between Ellie's house and school.
Interest accumulates whether he pays or not.
If he does not pay, the principal is not reduced, therefore the accumulated amount in 15 months is equal to
Future value = 13000(1+0.036/12)^15
=$13597.45 (to the nearest cent)