If 3.8 × 10-6 is added to 4.2 × 10-5 giving due regard to significant figures, then the result will be

Question

If 3.8 × 10-6 is added to 4.2 × 10-5 giving due regard to significant figures, then the result will be (A) 4.58 × 10-5 (B) 4.6 × 10-5 (C) 4.5 × 10-5 (D) 4.7 × 10-5

Tardigrade Admin · Accepted Answer

We will use the general rule of addition by making the powers same.
i.e., we add

3.8 \times 1 0^{- 6}

and

42 \times 1 0^{- 6}

, we get

45.8 \times 1 0^{- 6} = 4.58 \times 1 0^{- 5}

.
As least number of significant figures in given values are

2

, so we round off the result to

4.6 \times 1 0^{- 5}

.

Q. If $3.8 \times 1 0^{- 6}$ is added to $4.2 \times 1 0^{- 5}$ giving due regard to significant figures, then the result will be

$4.58 \times 1 0^{- 5}$

$4.6 \times 1 0^{- 5}$

$4.5 \times 1 0^{- 5}$

$4.7 \times 1 0^{- 5}$

Q. If 3.8×10−6 is added to 4.2×10−5 giving due regard to significant figures, then the result will be

4.58×10−5

4.6×10−5

4.5×10−5

4.7×10−5

We will use the general rule of addition by making the powers same. i.e., we add 3.8×10−6 and 42×10−6, we get 45.8×10−6=4.58×10−5. As least number of significant figures in given values are 2, so we round off the result to 4.6×10−5.

Q. If $3.8 \times 1 0^{- 6}$ is added to $4.2 \times 1 0^{- 5}$ giving due regard to significant figures, then the result will be

$4.58 \times 1 0^{- 5}$

$4.6 \times 1 0^{- 5}$

$4.5 \times 1 0^{- 5}$

$4.7 \times 1 0^{- 5}$