Approximately how many times larger is 6.4 × 10-8 than 4.8 × 10-12?

20

Step-by-step explanation:6.4 × 10-8=56

                                           4.8 × 10-12=36

                                                              -

                                                                 20 times larger

PART A : If you start solving it, it will looks like this: 4*6  - 5 ≤ 19 -> 19≤19 which is actually true because 19 is = to 19. 
But 19 < 19 because they're actually equal. 
2 :
PART A : 25 x = 930.75 
The number of ticker -> 25 The price of a ticket -> x ( as we don't know and it's what we are asked to find. 
930.75 is the total amount of money raised. 
PART B: 25 x = 930.75 
25 x : 25 = 930.75 : 25 
x= 37.23 £ 
To find out if this is correct, we replace ''x'' in the equation : 25 * 37.23 = 930.75 -> 930.75 = 930.75 
3. PART A  : x ≥ 18 
     PART B: You create the number line, put the number 18 on it and draw a circle which must be filled. The arrow's direction must be right, to + infinite ( I don't know if this is the way it must be described but English is not my native language)