Progressive diminishing size of diatoms is prevented by production of

A convex lens forms a real, diminished point sized image on focus. Then the position of the object is at

When there are diminishing returns to a factor, marginal and total product both always fall.

The sum of four numbers in arithmetical progression is 48 and the product of the extremes to the product of the means as 27 to 35 Find the numbers

The sum of four numbers in arithmetical progression is 48 and the product of the extremes to the product of the means as 27 to 35 Find the numbers