What is more useful when it is broken?

In particular commonwealth games, a female participant won silver and gold medals for a single event.

How can this be possible?

Rectify the following equality 101 - 102 = 1 by moving just one digit.

I have thought of a number that is made up by using all the ten digits just once. Here are a few clues for you to guess my number:

First digits is divisible by 1.
First two digits are divisible by 2.
First three digits are divisible by 3.
First four digits are divisible by 4.
First five digits are divisible by 5.
First six digits are divisible by 6.
First seven digits are divisible by 7.
First eight digits are divisible by 8.
First nine digits are divisible by 9.
The number is divisible by 10.

Can you find out the number ?

A doctor and a boy were fishing. The boy was the doctor’s son, but the doctor was not the boy’s father. Who was the doctor?

Two boys wish to cross a river. The only way to get to the other side is by boat, but that boat can only take one boy at a time. The boat cannot return on its own, there are no ropes or similar tricks, yet both boys manage to cross using the boat.

How?

Role Action
Block Prevents the target player from acting
Redirect Change target player target.
Save Protects the target player from death.
Seer Sees all actions that occurred
Murderer Kills the target player

The following five players are playing:

Andy
Brian
Chris
Daniel
Fred

You are Andy the Seer and you saw the following things:
a) Brian was redirected to Chris.
b) Chris was blocked.
c) Daniel was killed.

Who is the murderer then?

A famous swimmer can swim downstream in a lake in exactly 40 minutes with the lake current.
He can swim upstream in that lake in exactly 60 minutes against the lake current.
The length of the lake is 2 km.

How long he can cover the distance of one side at a still lake with no current?

When my father was 31 I was 8. Now he is twice as old as me. How old am I?

Can you name an animal whose killing cannot be performed without spilling your own blood?