GSEB Solutions for Class 9 Mathematics – Logarithm

GSEB Solutions for Class 9 Mathematics – Logarithm (English Medium)

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Exercise -18

Solution 1(1):

Solution 1(2):

Let a = 47.37 × 1.921 × 771
∴ log a
= log 47.37 + log 1.921 + log 771
= 1.6755 + 0.2835 + 2.8871
= 4.8461
∴ antilog(log a) = antilog(4.8461)
∴ a = 70170

Solution 1(3):

Solution 1(4):

Solution 1(5):

Solution 1(6):

Solution 1(7):

Let a = (51.32)⁵
∴ log a
= log (51.32)⁵
= 5 log 51.32
= 5(1.7103)
= 8.5515
∴ antilog(log a) = antilog(8.5515)
∴ a = 356000000

Solution 1(8):

Solution 1(9):

Solution 1(10):

Solution 2(1):

b. 89700
8.97 × 10⁴ = 8.97 × 10000 = 89700

Solution 2(2):

Solution 2(3):

Solution 2(4):

Solution 2(5):

Solution 2(6):

Solution 2(7):

b. 4
The characteristic of the number log 55231 is 4.

Solution 2(8):

c. 6
The characteristic of the number log 8989340 is 6.

Solution 2(9):

c. – 3
The characteristic of the number log 0.003942 is -3.

Solution 2(10):

d. -1
The characteristic of the number log 0.13879 is -1.