John needs to buy a collection of books for the course that he is studying. The individual prices of the books are $30, $35 and $45. There are three different bookshops that John could go to in order to buy the books, each of which will offer different discounts: The first shop sells all of the books at 10% less than the usual price. The second shop gives a discount of $10 on any purchase of $75 or more. The third shop gives a discount of 20% on any book that normally costs more than $40. John will buy all of the books at the same shop and will choose the shop that gives him the cheapest price. How much will John pay for the books?

shop 3 and he will pay 97$ for his books.

Explanation:

*% means of and of means to multiply and to discover the percent, we will divide by 100 in the end.

for ex.

10%40

step 1: multiply 10 by 40=400

step 2: divide by 100, so 400/100=4            * if u understand it then u can                        

10%percent of 40 is 4.                             skip these 2 steps and get the

Another ex.                                   answer with this trick.  for ex.  

10%73                                            10%99= 9.9 the trick is you move the left of

10*73=730              the second digit or in this scenario the underlined 9. you

730/100=7.3         can use this trick for any power of 10 but just remember                    

10%73=7.3             go left of the second digit depending on how many

                                 zeros the power of 10 has. (this trick is only helpful with

                                     power of 10's.

Shop 1:

step 1: find the percent of each individual prices

10%30=3 10%35=3.5 10%45=4.5

step 2: take 10% of the price and subtract it from the price.

30-3=27   35-3.5=31.5    45-4.5=40.5

step 3: add all the prices

27+31.5+41.5=99

the total price for this shop is $99.

Shop 2:

step 1: add all the prices

30+35+45=110

step 2: if the total price is above 75 then subtract 10.

110-10=100

the total price for this shop is $100.

Shop 3:

step 1: if you have a book that's over 40$ then take 20% out of the book.

20%40=8 then, 40-8=32

step 2: Add all the prices

30+35+32=97

The total price for this shop is $97.

In conclusion, the third shop gives him the books for the cheapest price for $97.

don't guess, because if you answer incorrectly, points are taken off. even if you don't finish, take your time. to study, use the sample questions. there is not much preparation to take the pre- tests.

i think the answer is c) ability to survive in high salinity.

hope it