The postage rates for sending parcels were $25 for the first 250g and $3.90 for additional 250g or part of 250g. how much did it cost to send a parcel weighting 830g?

Imagine a new pasture with grass growing on it. every day after the seeds have germinated, the number of blades of grass in the pasture triples. after 18 days, the entire pasture is completely covered in grass. how many days did it take for the pasture to be one-third covered in grass?

Write a corresponding real world problem to represent 2x - 125=400

For what values of the variable x is the expression square root of 7x+14+ square root of 7-x a real number?