Singapore 5th Grade Math Worksheet: 11 Average

Transcription

1 Singapore 5th Grade Math Worksheet: 11 Average Name: Date: Problem 1 Acrobat Adam is my math teacher. He asked me this question: a) What is the sum of the first 12 even numbers? b) What is their average? Problem 2 He asked me this question next: a) What is the total of the first 22 odd numbers? b) What is their average?

2 Problem 3 I was terribly sick yesterday for I had accidentally eaten a week-old maggotridden fungus-filled putrid pizza. When I saw the doctor, he too asked me a math question. a) What is the sum of the first 28 numbers? b) What is their average? Problem 4 The odd doctor asked me next: a) What is the sum of the first 36 odd numbers? b) What is their average?

3 Problem 5 Farmer Frank was a family man. He had 2 lovely wives and 2 lovely kids. He went mushroom hunting last Sunday and managed to collect 520 mushrooms. After giving some to his wives and sons, he had 6/13 of his mushrooms left. On average, how many mushrooms did Frank give each family member? Problem 6 Count Dracula had 330 wolves in his dusty castle. He fried some of his wolves on Saturday and invited Gary Ghoul, Witch Wanda and Vampire Wilfred for dinner. His ravenous friends wolfed down the fried wolves. The Count, however, didn't eat any because he was a vegetarian. If Count Dracula had 2/11 of his wolves left, how many wolves on average did each of his friends eat?

4 Problem 7 A truck from a factory spilled 4 liters of toxic waste just outside a mental asylum last month. Unluckily Sam, Tony, Joe and Harry jumped over the fence of the mental asylum that day and spotted the spill on the road. They began lapping it up eagerly. When they were finally caught by the guards, 3/8 of the toxic waste was left on the road. The next day, the inmates sprouted wings and flew to Hawaii. What was the average amount of toxic waste each mental patient had drunk? Problem 8 My mother went to the supermarket in April and bought a 75 kg sack of dried gecko tails. They were good for soups and stews. 1/4 of the gecko tails were left in September. How much dried gecko tails did we eat on average each month?

5 Problem 9 Hilda was an avid bird-watcher. She bought a 744 page book on birds on Sunday. She read an average of 155 pages per day. Before she woke up on Thursday morning, what fraction of the book hadn't she read? Problem 10 I had $1240 with me so I decided to visit Madagascar. I arrived in Madagascar on Friday morning and left the island on Tuesday night. I had a great time there chasing the local lemurs and black mambas. I spent on average $186 a day. When I came back home, what fraction of my money was left?

6 Problem 11 Inventor Idris invented an ingenious iguana itch inducing gadget. He made 1512 of those cool gadgets on Tuesday morning and began selling them door-to-door. On average, by every evening he would have sold 112 gadgets to happy customers. On Monday morning, what fraction of the gadgets was left? Problem 12 I absolutely had to catch 8000 Nile crocodiles and relocate them to Niagara Falls. My grandpa had made me promise to do that before he succumbed to crocodile flu last month. So last Sunday I flew to Africa and began catching those pesky creatures at 4.35 pm. I caught an average of 120 crocodiles per minute. At 5 pm, an irate bull crocodile tore off my left ear and I had to stop for a while to stitch my ear back. What fraction of the crocodiles hadn't I caught at that time?

7 Problem 13 Serial killer Sabilio went trick-or-treating on Halloween and came back home with 3 types of delicious candies. He had 460 more chocolate-covered skulls than sugarcoated eyes. The number of chocolate-covered skulls was also 320 more than dried twisted tongues. The average number of each type of candy was What was the average number of sugar-coated eyes and twisted tongues? Problem 14 My grandmother astounded everyone by balancing a washing machine, an LCD TV and a baboon on the tip of her nose at a local talent show last night. The mass of the washing machine was 10 kg more than the mass of the baboon and 26 kg more than the mass of the TV. The average mass of the 3 things she balanced was 55 kg. What was the average mass of the baboon and the TV?

8 Problem 15 Diana has 3 elderly dancing sheep that make a lot of money for her at Las Vegas. Their names are Bleat, Baa and Wolfmeat. Baa is 15 years older than Bleat and 3 years older than Wolfmeat. The average age of the 3 sheep is 46 years. What is the average age of Bleat and Wolfmeat? Problem 16 My father is a gravedigger. He employed 4 muscular imps to help him dig graves. Last week he weighed them and found that Blumba was 6 kg heavier than Grumba, 18 kg heavier than Dumba, and 12 kg heavier than Zumba. The average mass of the 4 imps was 77 kg. We heard devastating news last night. Greedy Blumba had eaten the filthy maggots of a rotting corpse and died. What is the average mass of the remaining imps?

9 Problem 17 A soldier was in enemy territory when he suddenly bumped into 6 midgets riding horses. He didn't shoot the midgets because they were cute. He asked them their ages. Their average age was 8 yr 8mth. Four of them dismounted to shake hands with the soldier. The ages of the four were 8 yr 2 mth, 7 yr 3 mth, 6 yr 9 mth and 6 yr 8 mth. What was the average of the the midgets still on their horses? Problem 18 9 howling werewolves entered our school at 11 am yesterday and attacked our shocked math teacher. The average mass of the 9 werewolves was 99.3 kg. 3 werewolves attempted to bite our teacher's ankles. Their masses were 92.4 kg, kg and 86.8 kg. The rest of the werewolves tried to bite off our poor teacher's ears. What was the average mass of the werewolves biting our teacher's ears?

10 Problem 19 Sean was surfing yesterday when suddenly a Tiger Shark tore off a huge chunk of his surfboard. Sean was lucky because 10 pretty mermaids killed the shark with their harpoons and saved him. The average mass of the mermaids was 52 kg 700 g. Four of the mermaids were redheads. Their masses were 46 kg 800 g, 49 kg 20 g, 53 kg 320 g and 50 kg 20 g. What was the average mass of the rest of the mermaids? Problem 20 Brian's mom cooked spicy centipede soup last week. She poured the soup into 8 bowls for there were 8 people in her family. The average amount of soup in each bowl was 3 liters 350 milliliters (3 l 350 ml). In 5 of the bowls however, the centipedes hadn't died and the family members who consumed the soup had a horrible stomachache later. The amount of soup in the 5 bowls was 2 l 800 ml, 3 l, 3 l 100 ml, 3.56 l and 3.87 l. The soup in the rest of the bowls didn t have live centipedes and no one who consumed them had to run to the toilet. What was the average mass of the soup in the rest of the bowls?

11 Answers Q1a - 156, Q1b - 13, Q2a - 484, Q2b - 22 Q3a - 406, Q3b , Q4a , Q4b - 36 Q5-70, Q6-90, Q7-625 ml, Q8-9 kg 375 g Q9-1/6, Q10-1/4, Q11-5/9, Q12-5/8 Q , Q14-49 kg, Q15-43 yr, Q16-74 kg Q17-11 yr 7 mth, Q kg Q19-54 kg 640 g, Q20-3 l 490 ml