Question

A small insect viewed through a convex lens is 1.8 cmcm from the lens and appears 2.5 times larger than its actual size. part a what is the focal length of the lens?

Answer 1

4.50

Explanation:

There's 2 total decimal places in both numbers.

Ignore the decimal places and complete the multiplication as if operating on two integers.

1 8

× 2 5

___________________

+ 9 0

+ 3 6

___________________

= 4 5 0Rewrite the product with 2 total decimal places.

Answer = 4.50

Therefore:

1.8 × 2.5 = 4.50