John deposited $2000 into a simple interest account. The account has a 7% annual interest rate. How much interest has he earned on this deposit at the end of six months? A $700

B $840

C $70

D $140

What is the smallest integer n such that n\sqrt{2} is greater than 20

Find the slope of the line y =8/9x + 1.

Find the volume of the described solid.the solid lies between planes perpendicular to the x-axis at x = 0 and x=7. the cross sectionsperpendicular to the x-axis between these planes are squares whose bases run from the parabolay=-31x to the parabola y = 30/x.a) 441b) 147c) 864d) 882