Question

The product of 1.7 × 10⁴ and 12.5 × 10^-6 is expressed in the standard form as k × 10ⁿ. The value of (2k + n) is
1. 2.25
2. 3.25
3. 2.125
4. 1.125

Answer 1

Correct Answer - Option 2 : 3.25

Given:

Two numbers are 1.7 × 104 and 12.5 × 10-6

Formula used:

a^b = a^c then b = c

Concept used: 

In the standard form, the decimal should be after one digit

Ex- 1.56 × 10³

Calculation:

The product of 1.7 × 104 and 12.5 × 10-6 = 21.25 × 10^-2 

⇒ 2.125 × 10 × 10^-2 

⇒ 2.125 × 10^-1 

Comparing it with the standard form k × 10n then,

k = 2.125 and n = -1

Now, (2k + n) = 2 × 2.125 + (-1)

⇒ 4.25 – 1 = 3.25

∴ The required value is 3.25