**GSEB Solutions for Class 7 Mathematics – Revision 1 (English Medium)**

GSEB SolutionsMathsScience

**Revision 1**

**Solution 1:**

1. Total number of saplings planted

= Saplings of Amla + Saplings of Gulmohar + Saplings of Asopalav + Saplings of Neem

= 6 + 18 + 21 + 15

= 60

2. 6 Saplings of Amla were planted.

3. Number of Asopalav Saplings = 21

4. Number of Gulmohar saplings = 18

Number of Neem saplings = 15

Thus, the number of Gulmohar saplings exceeding the number of Neem saplings

= Number of Gulmohar saplings – Number of Neem saplings

= 18 – 15

= 3

5. Number of Gulmohar saplings = 18

**Solution 2:**

1. Total number of runs scored

= Runs scored by Sachin + Runs scored by Ravindra + Runs scored by Sehwag + Runs scored by Parthiv

= 75 + 70 + 110 + 45

= 300

2. Sehwag scored 110 runs.

3. Number of runs scored by Sachin = 75

**Solution 3:**

1. ‘| |’ is the symbol to show the absolute value of a number.

2. (-3) + 6 = 6 + (-3)

3. 0 × (-100) = 0

Negative integer × Zero = Zero

4. (-4) × (-4) = 16

Negative integer × Negative integer = Positive integer

5. Absolute value of (-70) is 70.

6. 7 + (-7) = 0

Addition of an integer with its additive inverse is zero.

7. 1 × 15 = 15

8. 3 × (-4) × 5 = 3 × 5 × (-4)

**Solution 4:**

1.

24 = 2 × 2 × 2 × 3

Here, the prime factors 2 and 3 do not form pairs.

Hence, 24 is not a perfect square.

2.

81 = 3 × 3 × 3 × 3

Here, the prime factor 3 forms two pairs.

∴ 81 = 32 × 32

Hence, 81 is a perfect square.

3.

111 = 3 × 37

Here, the prime factors 3 and 11 do not form pairs.

Hence, 111 is not a perfect square.

4.

576 = 2 × 2 × 2 × 2 × 2 × 2 × 3 × 3

Here, the prime factors 2 and 3 form pairs.

∴ 576 = 22 × 22 × 22 × 32

Hence, 576 is a perfect square.

**Solution 5:**

- Square of 20 = 20
^{2}= 20 × 20 = 400 - Square of 25 = 25
^{2 }= 25 × 25 = 625 - Square of 12 = 12
^{2}= 12 × 12 = 144 - Square of 10 = 10
^{2 }= 10 × 10 = 100 - Square of 16 = 16
^{2 }= 16 × 16 = 256

**Solution 6:**

112 = 2 × 2 × 2 × 2 × 7

Here, the prime factor 7 does not form a pair.

Hence, to make a pair of 7, 112 should be multiplied by 7.

Thus, 112 × 7 = 2 × 2 × 2 × 2 × 7 × 7

By multiplying 112 by 7, we get pairs of all the prime factors.

Hence, 112 should be multiplied by 7 so that the product becomes a perfect square.

**Solution 7(1):**

**Solution 7(2):**

**Solution 7(3):**

**Solution 7(4):**

**Solution 7(5):**