Question

fillups in the blankso (12/5×-4/7) × 3/2= ×4/7×3/2​

Answer 1

Step-by-step explanation:

Question 1:

Solve:

(i) 2 – 3/5 (ii) 4 + 7/8 (iii) 3/5 + 2/7 (iv) 9/11 – 4/15 (v) 7/10 + 2/5 + 3/2

(vi) 2 + 3 (vii) 8 - 3

Answer:

(i) 2 – 3/5 = 2/1 – 3/5

= (2 * 5 – 3 * 1)/5 [LCM (1, 5) = 5]

= (10 - 3)/5

= 7/5

= 1

(ii) 4 + 7/8 = 4/1 + 7/8

= (4 * 8 + 7)/8 [LCM (1, 8) = 8]

= (32 + 7)/8

= 39/8

= 4

(iii) 3/5 + 2/7 = (3 * 7 + 2 * 5)/35 [LCM (7, 5) = 35]

= (21 + 10)/35

= 31/35

(iv) 9/11 – 4/15 = (9 * 15 – 4 * 11)/165 [LCM (11, 15) = 165]

= (135 - 44)/165

= 91/165

(v) 7/10 + 2/5 + 3/2 = (7 * 1 + 2 * 2 + 3 * 5)/10

= (7 + 4 + 15)/10

= 26/10 [26 and 10 are divided by 2]

= 13/5

= 2

(vi) 2 + 3 = 8/3 + 7/2

= (8 * 2 + 7 * 3)/6 [LCM (2, 3) = 6]

= (16 + 21)/6

= 37/6

= 6

(vii) 8 - 3 = 17/2 – 29/8

= (17 * 4 – 29 * 1)/8 [LCM (2, 8) = 8]

= (68 - 19)/8

= 39/8

= 4

Question 2:

Arrange the following in descending order:

(i) 2/9, 2/3, 8/21 (ii) 1/5, 3/7, 7/10

Answer:

(i) 2/9, 2/3, 8/21 = (2 * 7, 2 * 21, 8 * 3)/63 [LCM (9, 3, 21) = 63]

= (14, 42, 24)/63

= 14/63, 42/63, 24/63

Now, 42/63, 24/63, 14/63 [Arrange in descending order]

So, 2/3, 8/21, 2/9

(ii) 1/5, 3/7, 7/10 = (1 * 14, 3 * 10, 7 * 7)/70

= (14, 30, 49)/70

= 14/70, 30/70, 49/70

Now, 49/70, 30/70, 14/70 [Arrange in descending order]

So, 7/10, 3/7, 1/5

Question 3:

In a “magic square”, the sum of the numbers in each row, in each column and along the diagonals is the same. Is this a magic square?

Class_7_Maths_Fraction_&_Decimals_Representing_Fractions

(Along the first row 4/11 + 9/11 + 2/11 = 15/11)

Answer:

Sum of first row: 4/11 + 9/11 + 2/11 = 15/11 (Given)

Sum of second row: 3/11 + 5/11 + 7/11 = (3 + 5 + 7)/11 = 15/11

Sum of third row: 8/11 + 1/11 + 6/11 = (8 + 1 + 6)/11 = 15/11

Sum of first column: 4/11 + 3/11 + 8/11 = (4 + 3 + 8)/11 = 15/11

Sum of second column: 9/11 + 5/11 + 1/11 = (9 + 5 + 1)/11 = 15/11

Sum of third column: 2/11 + 7/11 + 6/11 = (2 + 7 + 6)/11 = 15/11

Sum of first diagonal (left to right): 4/11 + 5/11 + 6/11 = (4 + 5 + 6)/11 = 15/11

Sum of second diagonal (left to right): 2/11 + 5/11 + /11 = (2 + 5 + 8)/11 = 15/11

Since the sum of fractions in each row, in each column and along the diagonals is same, therefore it is a magic square.

Question 4:

A rectangular sheet of paper is 12 cm long and 10 cm wide. Find its perimeter.

Answer:

Given: The sheet of paper is in rectangular form.

Length of sheet = 12 cm = 25/2 cm

and Breadth of sheet = 10 cm = 32/3

Now, Perimeter of rectangle = 2 (length + breadth)

Answer 2

Answer:

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3+2=7 means (3*2)+1=7

5+4=23 means (5*4)+3=23

7+6=47 means (7*6)+5=47

9+8=79 means (9*8)+7=79

Now comes the tricky part. If you can see after multiplying the digits, which were given supposedly for addition, and adding 1,3,5,7 subsequently to each of them the resultant of them was 7,23,47,79.

Now, though it may seem like they are adding sequential odd numbers, ut they can be prime numbers too.

If they are odd numbers the next number in the sequence to be added would be 9, so that the answer would become 10+9=99 like (10*9)+9=99 concept.

{If they are prime numbers then the next number in the sequence to be added would be 11, so that the answer would become 10+9=101 like (10*9)+11=101.}

So finally, to the given puzzle according to the logic explained answer is 99

hope it helps uhhhhhh(: