Sign conventions of concave and convex lens​

Explanation:

The New Cartesian Sign Convention of Concave and Convex Lens

According to the sign convention, a convex lens focal length is positive, whereas a concave lens focal length is negative. The incident light always moves from left to right because the object is always on the lens's left side.

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multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color).

get the total number of pieces of fruit and divide it by 4 to get the average. the result is the answer to the problem. 14 total number of fruits and there are 4 members. 14 divided by 4 is equals to 3.5.