Increase £1.45 by £1.65. 2. What is the cost of 25 cm at £1.20 per metre? 3. This clock is 20 min fast. Write the correct time in digits. Use a.m. or p.m. 4. Find the total cost of two toy cars each c

$$
\pounds 1.45 + \pounds 1.65 = \pounds 3.10
$$
The increased amount is $\boxed{\pounds 3.10}$.

There are $100 \text{ cm}$ in $1 \text{ m}$.
$$
25 \text{ cm} = \frac{25}{100} \text{ m} = 0.25 \text{ m}
$$

Multiply the length in meters by the cost per meter.
$$
0.25 \text{ m} \times \pounds 1.20/\text{m} = \pounds 0.30
$$
The cost is $\boxed{\pounds 0.30}$.

The hour hand is between 7 and 8. The minute hand is pointing at 3, which represents 15 minutes past the hour. Since it says "morning", the time shown is 7:15 a.m.

$$
7:15 \text{ a.m.} - 20 \text{ minutes}
$$
Subtracting 15 minutes brings it to 7:00 a.m.  
Subtracting another 5 minutes (20 - 15 = 5) brings it to 6:55 a.m.  
The correct time is $\boxed{6:55 \text{ a.m.}}$.

$$
2 \times \pounds 1.38 = \pounds 2.76
$$
The total cost is $\boxed{\pounds 2.76}$.

For unit fractions (fractions with a numerator of 1), the fraction with the largest denominator is the smallest.  
Comparing the denominators (2, 7, 4, 10, 3), the largest denominator is 10.  
Therefore, the smallest fraction is $\frac{1}{10}$.

$$
1 - \frac{1}{10} = \frac{10}{10} - \frac{1}{10} = \frac{9}{10}
$$
The smallest fraction is $\boxed{\frac{9}{10}}$ less than a whole one.