A clothing shop manufactures and sell cloth face masks directly to the public in response to the initiative of curbing the spread of coronavirus. The profit from selling

number of masks each week is , where

= 100 − 1

2 2 − 200

By completing the square, find the greatest profit the shop can make each week,

and how many masks it has to sell each week to achieve this profit.​

The table below shows the approximate masses of a dust particle and a grain of pollen. dust particle 0.000000778 g grain of pollen 0.00000000155 g the mass of a dust particle can be estimated and written in the form a × 10^b, where a = 8 and b = the mass of a grain of pollen can be estimated and written in the form a × 10^b, where a = 2 and b = based on the estimates, the mass of a dust particle is approximately blank times larger than the mass of a grain of pollen.