Pls answer 10 points

Suppose there is a relation r(a, b, c) with a b+-tree index with search keys (a, b).1. what is the worst-case cost of finding records satisfying 10 < a < 50 using this index, in terms of the number of records n1, retrieved and the height h of the tree? 2. what is the worst-case cost of finding records satisfying 10 < a < 50 and 5 < b < 10 using this index, in terms of the number of records n2 that satisfy this selection, as well as n1 and h defined above? 3. under what conditions on n1 and n2, would the index be an efficient way of finding records satisfying the condition from part (2)?

The ratio of men to women in a certain factory is 3 to 4 .there are 210 men. how many workers are there?

4.9: population write a program that will predict the size of a population of organisms. the program should ask the user for the starting number of organisms, their average daily population increase (as a percentage, expressed as a fraction in decimal form: for example 0.052 would mean a 5.2% increase each day), and the number of days they will multiply. a loop should display the size of the population for each day. prompts, output labels and messages. the three input data should be prompted for with the following prompts: "enter the starting number organisms: ", "enter the daily increase: ", and "enter the number of days the organisms will multiply: " respectively. after the input has been read in successfully, a table is produced, for example: 2 300.0 4 675.0 under the heading is a line of 29 dashes followed by one line for each day, showing the day number and the population at the beginning of that day. input validation. do not accept a number less than 2 for the starting size of the population. if the user fails to satisfy this print a line with this message "invalid. must be at least 2. re-enter: " and try to read the value. similarly, do not accept a negative number for average daily population increase, using the message "invalid. enter a non-negative number: " and retrying. finally, do not accept a number less than 1 for the number of days they will multiply and use the message "invalid. enter 1 or more: ".