What is the math question 2/5+?=7/10

What is the most accurate measurement of 1 pound

During a bike challenge riders have to collect various colored ribbons each 1/2 mile they collect a red ribbon each eighth mile they collect a green ribbon and each quarter mile they collect a blue ribbion wich colors of ribion will be collected at the 3/4 markrer

Find the equation of the line with slope =8 and passing through (6,53) write your equation in the form y=mx+b