Question

. A clock strikes once when its hour hand is at 1, twice when it is at 2 and so on. How many times does the clock strike in six hours?

Answer 1

it will strike 6n+21 times
n=hours hand at starting

Answer 2

1 o'clock=1 time

2 o'clock=2 times

3 o'clock=3 times

4 o'clock=4 times

5 o'clock=5 times

6 o'clock=6 time

therefore no. of times it strikes in 6 hours=1+2+3+4+5+6=21 times