Given
Lunch Break = 1 hour
From 10 a.m. to 5.45 p.m = 12.00 - 10:00 = 2.00 +  5.45 = 7.45
lunch break - 1.00 = 6.45
Also given, the post office works for 6 days a week.
Total duration of working hours in a week = 6.45 \(\times\) 6
= 6 hours 45 min \(\times\) 6 = 36 hours 270 minutes
= 270/60 = 4 30/60 = 4 1/2 hr.
= (36 + 4) hours 30 min.
Total Working hours = 40 hours 30 min.

i) (Rectangle Shape)
A door has 1m wide and 2 m 50 cm high.
Therefore l = 2 m 50 cm = 250 cm
b = 1 m = 100 cm
Area = I \(\times\) b = 250 \(\times\) 100 = 25000 cm²
ii) A bed have 2 m and 20 cm length and 90 cm wide.
Therefore I = 2 m 20 cm = 220 cm
b = 90 cm
Area = I \(\times\) b = 220 \(\times\) 90 = 19,800 cm²
Area of door > Area of a bed
Yes, we can take a bed into the room,

The saplings are planted at a distance = 2 m 50 cm = 2 m 50 cm
The road of length = 5 km = 5000 m
= 5000 \(\times\) 100
= 500000 cm
No. of Saplings = 2560

= 2000 saplings will be planted by him.
Therefore 560 saplings are left.

(i) The Vaigai Express, Start from Chennai = 13.40 hours
Arrive at Madurai - 21.20 hours
(ii)  8 halts.
(iii) 5 minutes
(iv)  20 : 34 hours
(v) 21 : 20 = 13 : 40 - 7: 40
 so, 7 hours 40 mins

526 ml = \(526.0\times \frac { 1 }{ 1000 } l\)                     1l = 1000 ml
                  \(\frac { 1 }{ 1000 } l=1\ ml\)

Quantity of water drunk by the calf = 5.750 l    1l = 1000 ml

= 5750 ml

weight of Murali's bag = 3 kg and 450 g ,
= (3 \(\times\) 1000 g) + 450 g                1 Kg = 1000 g
= 3000 g + 450 g
= 3450 g

weight of a tablet = 650 mg
\(=650.0\times \frac { 1 }{ 1000 } g\)      (1 g = 1000 mg)
 (\(\frac { 1 }{ 1000 } \)g = 1 mg)