The population of Kingwood was 374,960 people when Zane moved there. Currently it is 20% smaller. What is the current population?

What is the remainder when 2872 is divided by 76? a) 51 b) 57 c) 60 d) 63

I'm confused on this could anyone me and show me what i need to do to solve it.

You are standing next to a really big circular lake. you want to measure the diameter of the lake, but you don't want to have to swim across with a measuring tape! you decide to walk around the perimeter of the lake and measure its circumference, and find that it's 400\pi\text{ m}400? m. what is the diameter dd of the lake?