3RD GRADE MATH PRACTICE FOR KANGAROO

Problem 1

Given that ▲ +▲ + 6 = ▲ + ▲ + ▲ + ▲Which number should replace ▲ ?

A)  2    B)  3      C)  4     D)  5      E)  6

Solution :

▲ +▲ + 6 = ▲ + ▲ + ▲ + ▲

Cancelling two triangles on both sides, we get

6 = ▲ + ▲

One ▲ = 3

Problem 2 :

Maria folds a square piece of paper in such a way the kangaroos exactly overlap each other. Along how many straight lines shown is this possible ?

A)  0      B)  1    C)  2      D)  3      E)  6

Solution :

Folding horizontally and vertically it is possible. Diagonally it is not possible.

Problem 3 :

Matthias and Klara live in a tower block. Klara lives 12 floors above Matthias. One day Matthias climbs the stair case to visit Klara. When halfway he is on the 8th floor. On which floor does Klara live ?

A)  12th   B) 14th     C)  16th     D)  20th    E) 24th

Solution :

Let x be the position of Matthias in tower block. Klara's position at tower block is x + 12.

Halfway of Klara's position = [x + (x + 12)] /2

(2x + 12)/2 = 8

2x + 12 = 16

2x = 16 - 12

2x = 4

x = 2

Klara lives in = x + 12 th floor

= 2 + 12

= 14 th floor

So, option B is correct.

Problem 4 :

A large cube is made from 64 small cubes. The 5 visible faces of the large cube are green, the bottom face is red. How many of the small cubes have 3 green faces ?

A)  4     B)  8    C)  16    D)  20

Solution :

Three visible faces in the color of green.

Problem 5 :

Kangi walks directly from zoo to school(Schule) and counts the flowers along the way. Which of the following numbers can he not obtain in this way ?

A)  9    B)  10    C)  11    d) 12   E)  13

Number of flowers in each blocks

1, 2, 3, 8, 5

In four different ways, it can reach the destination.

• Way A = 1 + 3 + 8 = 12
• Way B = 1 + 3 + 5 = 9
• Way C = 2 + 3 + 8 = 13
• Way D = 2 + 3 + 5 = 10

In this ways, we cannot obtain the number 11. So, option C is correct.

Problem 6 :

A ferry boat can transport, in one journey, either 10 cars and 6 lorries. Yesterday the boat crossed the rivers 5 times. It was always fully loaded and transported a total of 42 vehicles, how many of these were cars ?

A)  10    B)  12    C)  20     D)  22     E)  30

Solution :

Number of vehicles transported in Trip 1 = 10 cars

Number of vehicles transported in Trip 2 = 10 cars

Number of vehicles transported in Trip 3 = 10 cars

Number of vehicles transported in Trip 4 = 6 lorries

Number of vehicles transported in Trip 5 = 6 lorries

Since it was fully loaded all the time, we create the list above

total number of vehicles transported = 10 + 10 + 10 + 6 + 6

= 30 + 12

= 42

So, 30 vehicles were cars. Option E is correct.

Problem 7 :

Hans began a chain -email. He sent an email to his friend Peter, who sent 2 it on to 2 more people, Each person that receives the email should send it to 2 more people. After 3 rounds 1 + 2 + 4 = 7 people have received the email after 5 rounds ?

A)  15    B)  16     C)  31    D) 33      E)  63

Solution :

After 5 rounds, number of emails sent = 1 + 2 + 4 + 8 + 16

= 31

So, option C is correct.

Problem 8 :

On the play ground some children measure the length of playground with their strides. Anni takes 15 strides, Betty 17, Dennis 12 and Ivo 14. Who has the longest stride ?

A)  Anni   B) Betty   C) Denis

D)  Ivo    E)  not possible to answer

Solution :

To walk with long steps, the stride is the distance between long steps.

Distance between the longest steps by Anni = 15

Distance between the longest steps by Betty = 17

Distance between the longest steps by Dennis = 12

Distance between the longest steps by Ivo = 14

Here Dennis will take long time to measure the length of the play ground.

So, option C is answer.

Problem 9 :

Write the number must replace the question mark, if the total of the numbers in each row is is the same ?

A)  99       B)  100     C)  209          D)  289        E)  299

Solution :

Observing the values in the table, 

by increasing 10 in each values of first row, we will get values in the second row.

99 + 100 = 199