Define I dioptre of newer of a lefts Ans. 1 dioptre is the power of a lens whose focal length is 1 metre.

1 D = 1 m

What are the differences between similar triangles and congruent triangles?

What are Armstrong numbers?

All real numbers are rational numbers.

A) True

B) False

The L.C.M of the smallest 2 digit composite number and the smallest composite number is:

• (a) 12
• (b) 4
• (c) 20
• (d) 44

Are all natural numbers also whole numbers?