Which explains whether the sum of 0.52 + 0.61 is less than or greater than one

Which of the following is most likely the next step in the series? a3z, b6y, c9x, d12w, е15v, f18u

Prove that 16^4-2^13-4^5 is divisible by 11.

Point r divides in the ratio 1 : 5. if the coordinates of e and f are (4, 8) and (11, 4), respectively, what are the coordinates of r to two decimal places?