Total distance = 2.87 km
                        = 2.87 × 1000 m
                        = 2870 m
Distance covered = 1500 m

Remaining distance  = 2870 - 1500
                                  = 1370 m

$1370m=\frac{1370}{1000}=1.37km$

Given number is 123.456 
Digit in the Hundreds place:       1          
Digit in the Tens place:               2        
Digit in the Ones place:              3        
Digit in the Tenths place:            4
Digit in the Hundredths place:    5
Digit in the Thousandths place:  6                

So, the digit at tenths place in 123.456 is 4.

The number between 0.754646 and 0.755646 must be greater than 0.754646 and smaller than 0.755646. In 0.756446, 0.756464 and 0.756647, digits till hundredth place are same but digit at ten thousandth place is greater than that of 0.755646. So, they are greater than 0.755646. So, only 0.755464 can be the answer.

60 minutes = 1 hour

1 minute = $\frac{1}{60}$ hour

45 minutes = 45 × $\frac{1}{60}$ 
                   = $\frac{45}{60}$
                   = 0.75 hours 

So, 5 hours and 45 minutes $=(5+0.75)=5.75$ hours

 The product of 9.52 and 9.82 is given by:
Here multiplicands have 2 decimal places each. Hence, the product will have 4 digits after the decimal point.
Therefore, 93.4864 is the answer.

       
         68.2305

  +   574.3330

  +     96.0020  

        738.5655
____________

$13+\frac{7}{10}$ + $\frac{3}{1000}=13+0.7+0.003$
                          $=13.703$

Multiplying $\frac{7}{4}$ with 25 on numerator and denominator to make denominator as 100.
$=\frac{7\times 25}{4\times 25}$ 
$=\frac{175}{100}=1.75$ 
$\therefore \frac{7}{4}=1.75$

13.9 = 13.90 ;
Therefore, digit at hundredths place = 0.

Cost per chocolate = $\frac{\text{Total cost}}{\text{Number of chocolates}}$
                            =  $\frac{100.65}{15}$
                            = Rs. 6.71