# Decimal Numbers Quiz Set 004

### Question 1

What is x in \${722/0.0722} = {7.22/x}\$?

A

\$7.22 × 10^{-4}\$.

B

\$7.22 × 10^{-3}\$.

C

\$7.22 × 10^{-2}\$.

D

\$7.22 × 10^{-5}\$.

Soln.
Ans: a
Transposing, x = \$7.22 × {0.0722/722}\$ which gives 0.000722, which, in scientific form is \$7.22 × 10^{-4}\$.

### Question 2

What is \${(-27) × 9.6 - 73 × (-3.6)}/9.6\$?

A

\${3/8}\$.

B

\${1/8}\$.

C

\${5/8}\$.

D

\${7/8}\$.

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: \${(-27) × 96 - 73 × (-36)}/96\$. We can now simpilfy the minus signs to get \${(73 × 36) - (27 × 96)}/96\$ which equals \${3/8}\$

### Question 3

Which is the smallest?

A

\$0.3^3\$.

B

\$1/0.3\$.

C

\$0.3\$.

D

\$0.3^2\$.

Soln.
Ans: a

We know that if a number is less than 1, then it becomes smaller and smaller as it is raised to higher and higher positive powers. Now, \$1/0.3\$ is same as \$0.3^{-1}\$. The three powers of 0.3 given to us are -1, 1, 2 and 3. Out of these 3 is the most positive, so, \$0.3^3\$ is the smallest.

### Question 4

What is \$93{97/100000}\$?

A

93.00097.

B

91.00097.

C

93.97000.

D

93.0097.

Soln.
Ans: a

The given expression can be written as \${93 × 100000 + 97}/100000\$ which is same as \$9300097/100000\$ which gives 93.00097

### Question 5

What is z in \$6.599 + 0.3 - z = 0.04\$?

A

6.859.

B

0.4.

C

4.0.

D

8.659.

Soln.
Ans: a

z = (0.3 + 6.599) - 0.04 = 6.859.