Thinking Quiz 10th

How many times can you find the number 5 if you write down all the numbers from 1 to 100?

• 19

• 20

• 10

• 15

• 50

Answer explanation

From 1 to 100, there are ten numbers with 5 as the unit's digit – 5, 15, 25, 35, 45, 55, 65, 75, 85, 95 and 10 numbers with 5 as the ten's digit - 50, 51, 52, 53, 54, 55, 56, 57, 58, 59.

An animal psychologist has been asked to visit the local zoo to see how the animals are going. She finds out that:

 

·      All the tigers were happier than the lions.

·      The penguins were lonelier than the tigers.

·      Some of the lions were lonelier than the penguins.

 

Which one of the sentences can be concluded from the above information?

• The tigers were happier than the penguins.

• The penguins were all less happy than the tigers.

• Some of the lions were lonelier than the tigers.

• The lions were all less lonely than the tigers.

Answer explanation

Tip: Don’t conflate “loneliness” with “happiness.” Just because animals are lonelier doesn’t mean they are less happy and vice versa.  

 

Because all the penguins were lonelier than the tigers and some of the lions were lonelier than the penguins, some of the lions were definitely lonelier than the tigers.

Rearrange the jumbled words to find out which word does not belong in the sentence.

Tom / breakfast / hearty/ eating / for / pancakes / enjoys

• hearty 

• for

• enjoys

• pancakes

• Eating

Answer explanation

Rearranging the words to form the sentence: Tom enjoys eating pancakes for breakfast. 

The extra word is “hearty”

Jacob has 2 more than double Kayleigh's number of marbles. 

If Kayleigh has 5 marbles, how many marbles does Jacob have?

• 29

• 12

• 24

• 20

• 10

Answer explanation

Kayleigh has 5 marbles. Jacob has double that number, plus 2. Therefore Jacob has 12 marbles.

Find the missing number in the series: 

2, 5, 7, 9, _ , 13, 15

• 8

• 11

• 10

• 12

Answer explanation

The series is increasing by 2.

therefore 9 +2 = 11

Alternatively, the sereis is listing odd numbers.

In a code language, '134' means “big and small”; '478' means 'eat big apples,’ and '729' means 'apples are red'. 

Which of the following digits stands for 'eat'?

• 8

• 4

• 7

• 1

• 9

Answer explanation

In the first and second sentences, the common code digit is '4', and the common word is 'big'; therefore, 4 stands for big. 

In the second and third sentences, the common code digit is '7,' and the common word is 'apples,’ so 7 means apples. 

Thus, in the second sentence, '8' means 'eat.’

In a certain language ‘526’ means ‘grass is green, ‘24’ means ‘green color’ and ‘436’ means ‘color is vibrant. 

Which digit in that language means ‘vibrant’? 

• 5

• 2

• 6

• 3

Answer explanation

In “24” which means “green color”, the digits not present in “526” which means “grass is green”, corresponds to color; therefore color is 4. Comparing “grass is green” and “color is vibrant” we find that “is” is the common word and hence corresponds to number 6. Therefore, if “color” is 4 and “is” is 6, vibrant must be 3. 

This is the partial price list for the local super-market. 

If I bought 2 kg of meat, 2 kg of bread and half a kg of apples. How much did it cost?

• $6.50

• $3.40

• $2.05

• $11.95

• $12.00

Answer explanation

Total cost = 5 kg of meat + 2 kg of bread + ½ kg of apples 

= (2 × 3.25) + (2 × 1.70) + 1/2 × 4.10

= 6.5 + 3.40 + 2.05 

= $11.95

Travis has 5 more than double Mike's number of marbles. 

If Mike has 17 marbles, how many marbles does Travis have?

• 29

• 39

• 41

• 34

Answer explanation

Mike has 17 marbles. Travishas double that number, plus 5. Therefore Travis has 39 marbles.

Mrs. Jenkins is analysing the results of her children in Maths, English, and Science from before and after test practice. Which child did not improve his/her average considering the results in all three subjects?

• Tyler

• Alicia

• Hugo

• Sheila

Answer explanation

Tip: Calculate each child's average originally and then the new average. You can do this by adding their scores together in a subject and dividing the total by 3.

Tyler is the only student whose results did not improve.