Two trains of length 270 m and 300 m travelling at 54 km/h and 36 km/h respectively, enter a two-track tunnel 430 m long simultaneously on different tracks and from opposite directions. After they cross each other, in how much time will the tunnel be free of the trains?

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?