What is more useful when it is broken?

A finger goes in me. You fiddle with me when you're bored. The best man always has me first. What am I?

Find The Next Number in the series:

12 13 15 17 111 113 117 119 123 ?

What does below chemistry rebus means?

How many triangles are there in the picture below?

A brand new Mobile Phone was on sale at 20% as a promotional offer. By what per cent must the Mobile price be increased to sell it at the original price again?

I have eight fingers and two thumbs but I do not live. What Am I?

Find three whole, positive numbers that have the same answer when multiplied together as when added together.

What do you think with the below Picture ?

In a concert, Christina is performing a dance show with her group.
At 10:00, she and her crew were dancing in an absolutely straight line. At that time Christina was standing in 4th position from both the front and back end of the row.

What was the size of her crew?