There are 10 books on the table. Two-fifths of them are reading books and three-tenths of them are math books. There is one fewer science book than math books and the rest are history books. How many history books are there?

Out of the 10 books, 10 x 2/5 =

<<10*2/5=4>>4 are reading books. While 10 x 3/10 = <<10*3/10=3>>3 are math books. There are 3 - 1 = <<3-1=2>>2 science books. So, the total number of reading, math, and science books is 4 + 3 + 2 = <<4+3+2=9>>9. Thus, there is only 10 - 9 = <<10-9=1>>1 history book. #### 1 Jake decides to go to the beach for a fun day. It is a 2-hour drive each way. He then spends 2.5 times at long at the beach as his total driving time. How much time does the trip take? He drives for a total of 2*2=<<2*2=4>>4 hours So he spends 4*2.5 =<<4*2.5=10>>10 hours at the beach That means the total trip took 10+4=<<10+4=14>>14 hours #### 14 James spends 30 minutes twice a day on meditation. How many hours a week does he spend meditating? Each session is 30/60=<<30/60=.5>>.5 hours So she spends .5*2=<<.5*2=1>>1 hour a day So she spends 1*7=<<1*7=7>>7 hours a week #### 7 Each yogurt is topped with 8 banana slices. One banana will yield 10 slices. If Vivian needs to make 5 yogurts, how many bananas does she need to buy? To make the yogurts, Vivian needs 5 x 8 = <<5*8=40>>40 banana slices. She needs to buy 40 / 10 = <<40/10=4>>4 bananas. #### 4 Jodi starts off walking 1 mile a day for 6 days a week. On the second week, she walks 2 miles a day, 6 days a week. On the third week, she walks 3 miles a day, 6 days a week. Finally on the fourth week, she walks 4 miles a day, 6 days a week. How many miles has she walked in 4 weeks? The first week she walked 1 mile, 6 days a week for a total of 1*6 = <<1*6=6>>6 miles The second week she walked 2 miles, 6 days a week for a total of 2*6 = <<2*6=12>>12 miles The third week she walked 3 miles, 6 days a week for a total of 3*6 = <<3*6=18>>18 miles On the fourth week, she walked 4 miles, 6 days a week for a total of 4*6 = <<4*6=24>>24 miles Over four weeks she has walked 6+12+18+24 = <<6+12+18+24=60>>60 miles #### 60 A vampire drains three people a week. His best friend is a werewolf who eats five people a week, but only fresh ones, never drained ones. How many weeks will a village of 72 people last them both? The vampire and werewolf need 3 + 5 = <<3+5=8>>8 people a week. A village of 72 people will last them both 72 / 8 = <<72/8=9>>9 weeks. #### 9 Mr. Ha owns 5 more silver dollars than Mr. Phung. Mr. Phung has 16 more silver dollars than Mr. Chiu has. If Mr. Chiu has 56 silver dollars, how many silver dollars the three have in total? Mr. Chiu has 56 silver dollars. If Mr. Phung has 16 more silver dollars than Mr. Chiu, then his total silver dollars is 56+16 = <<16+56=72>>72 The total number of silver dollars that Mr. Ha owns is 72 +5= <<72+5=77>>77 Combined, together they have 77+72+56 = <<77+72+56=205>>205 silver dollars #### 205 Lionel went to the grocery store and bought 14 boxes of Graham crackers and 15 packets of Oreos. To make an Oreo cheesecake, Lionel needs 2 boxes of Graham crackers and 3 packets of Oreos. After making the maximum number of Oreo cheesecakes he can with the ingredients he bought, how many boxes of Graham crackers would he have left over? Lionel has enough Graham crackers to make 14/2 = <<14/2=7>>7 Oreo cheesecakes Lionel has enough Oreos to make 15/3 = <<15/3=5>>5 Oreo cheesecakes Therefore, the maximum number of cheesecakes Lionel can make is 5. Lionel needs 2 * 5 = <<2*5=10>>10 boxes of Graham crackers to make 4 cheesecakes He'll have 14 - 10 = <<14-10=4>>4 boxes left over #### 4 Lucas wants to get a dog but his parents think he already has too many pets and won't have enough space. He already has 12 pet beds in his room but manages to fit another 8 pet beds. His parents argue that each pet is going to need 2 beds each to feel comfortable. According to his parent's argument, how many pets does Lucas have enough room for? Lucas has a total of 12 existing pet beds + 8 new pet beds = <<12+8=20>>20 pet beds. So according to his parents, Lucas has enough room for 20 pet beds / 2 pet beds per pet = <<20/2=10>>10 pets. #### 10 To raise money, a school is selling ice-pops for $1.50. It costs 90 cents to make each pop, and the money from the pops will be used to buy pencils, which cost $1.80 each. How many pops must be sold to buy 100 pencils? To buy 100 pencils the school needs 100 * $1.80 = $<<100*1.80=180.00>>180.00. Each ice pop sells for $1.50 but costs $.90 to make, for a net profit of $1.50 - $.90 = $<<1.50-.90=.60>>.60. So in order to raise $180.00, the school will need to sell $180.00 / $.60 per ice-pop = <<180/.60=300>>300 ice-pops. #### 300