Question

Where will the hand of a clock stop if it

1. starts at 10 and makes $\frac{1}{2}$ of a revolution, clockwise?

2. starts at 4 and makes $\frac{1}{4}$ of a revolution, clockwise?

3. starts at 4 and makes $\frac{3}{4}$ of a revolution, clockwise?

Answer 1

Time taken for $1$ revolution$=60$ minutes

Time taken for $1/2$ revolution$=30$ minutes

Time taken for $1/4$ revolution$=15$ minutes

Time taken for $3/4$ revolution$=45$ minutes

(a) The hand of the clock starts at $10$ and stops after $\frac{1}{2}$ revolution clockwise.

$\therefore$ The hand of the clock stops at $10+60$ minutes.

$=10+1$ hr

$=11$

(b) The hand of the clock starts at $4$ and stops after $1/4$ revolution clockwise.

$\therefore$ The hand of the clock stops at $4+30$ minutes.

$=4:30$.

(c) The hand of the clock starts at $4$ and steps after $3/4$ revolution clockwise.

$\therefore$ The hand of the clock stops at $4+45$ minutes

$=4:45$.