Shanice used the same amount of shampoo each day. After 7 days, 4/5 of the bottle was left; after 15 days, 280 ml was left. Find the amount at first.
Opening the drawing…
MathBrush is being tested with a few parent groups, and every solution on the site is open to them. If you were given a code, it goes in once and this device remembers it. 65 worked examples are free to everyone without one.