Q 3) Solve the following:

1) Using divisibility test determine which of the following numbers are divisible by 11. (THIS IS TOUGH QUESTION FOR STD VI)

a) 61809

First: Add alternate digits = 6 + 8 + 9 = 23

Second: Add remaining digits = 1 + 0 = 1

Subtracting first from second we get 23 -1 = 22 which is divisible by 11 hence the number 61809 is divisible by 11

b) 7138965

First: Add alternate digits = 7 + 3 + 9 + 5 = 24

Second: Add remaining digits = 1 + 8+ 6 = 15

Subtracting first from second we get 24 - 15 = 9 which is not divisible by 11, hence 7138965 is not divisible by 11.

2) Find the least number which when divided by 12, 16 and 24 and 36 leaves a remainder 7 in each ( School should have asked only to find LCM no need of inserting remainder 7, too Tough for Students)

Answer: Find LCM

2| 12     16      24    36

 2 |  6       8       12     18 

 2  |    3      4        6       9

2    |     3      2        3       9

3     |      3       1       3        9

3      |       1       1        1       3

       |         1      1         1       1

Therefore LCM = 2 x 2 x 2 x 2 x 3 x 3 = 144

Now to leave the remainder 7 we add 7 to LCM 144 therefore 144 + 7 = 151 is the answer.

3) In the given diagram name the points

i) in the interior of DOE

ii) in the exterior of EOF

iii) on EOF

(THIS QUESTION REFER TO CLASS TEACHER)

4) Draw rough diagrams for 2 angles such that they have

a. one point in common

b. one ray ub common (PLEASE REFER THIS TO TEACHER I AM NOT SURE OF THE CORRECT ANSWER)

5) Classify the angle into acute, obtuse and right angle

i) 40 degrees = acute angle

ii) 160 degrees = obtuse angle

iii) 90 degrees = right angle

iv) 3 degrees = acute angle

v) 65 degrees = acute angle

vi) 110 degrees = obtuse angle

6) Find

a) 23 - (-12) here -(-12) becomes + 12

so we have 23 + 12 = 35

b) -36 - (-50) here - (-50) becomes +50

so we have -36 + 50 = 50 -36 (here i have only reversed the sum)  = 14