# Decimal Numbers Quiz Set 002

### Question 1

What is 0.0061 × 0.84?

A

\$5.124 × 10^{-3}\$.

B

\$5.124 × 10^{-2}\$.

C

\$5.124 × 10^{-1}\$.

D

\$5.124 × 10^{-4}\$.

Soln.
Ans: a

### Question 2

14687 is same as?

A

\$1.4687 × 10^{4}\$.

B

\$1.4687 × 10^{3}\$.

C

\$1.4687 × 10^{5}\$.

D

\$1.4687 × 10^{2}\$.

Soln.
Ans: a

### Question 3

What is \${42 × 1.9 - 68 × 5.2}/9.1\$?

A

\$-30{8/91}\$.

B

\$-30{7/91}\$.

C

\$-30{6/91}\$.

D

\$-30{9/91}\$.

Soln.
Ans: a

Observe that all fractional numbers are having one digit to the right of the dot. So we can cancel all the dots and get a plain expression: \${42 × 19 - 68 × 52}/91\$ which equals \${-2738/91}\$, which is same as: \$-30{8/91}\$

### Question 4

What is z in \$2.285 + 0.4 - z = 0.02\$?

A

+2.665.

B

-2.665.

C

+2.556.

D

-2.556.

Soln.
Ans: a

z = (0.4 + 2.285) - 0.02 = 2.665.

### Question 5

What is x in \${149/0.0149} = {1.49/x}\$?

A

\$1.49 × 10^{-4}\$.

B

\$1.49 × 10^{-5}\$.

C

\$1.49 × 10^{-3}\$.

D

\$1.49 × 10^{-2}\$.

Soln.
Ans: a
Transposing, x = \$1.49 × {0.0149/149}\$ which gives 0.000149, which, in scientific form is \$1.49 × 10^{-4}\$.