Write down the first 5 terms of the AP with first term 2 and common difference-5

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?

The sum of the speeds of two trains is 720.2 mph. if the speed of the first train is 7.8 mph faster than the second train, find the speeds of each.

If a distance of 75 yds is measured back from the edge of the canyon and two angles are measured , find the distance across the canyon angle acb = 50° angle abc=100° a=75 yds what does c equal?