# Decimal Numbers Quiz Set 018

### Question 1

Which is the smallest?

A

\$0.001^3\$.

B

\$1/0.001\$.

C

\$0.001\$.

D

\$0.001^2\$.

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, \$1/0.001\$ is same as \$0.001^{-1}\$. The three powers of 0.001 given to us are -1, 1, 2 and 3. Out of these 3 is the most positive, so, \$0.001^3\$ is the smallest.

### Question 2

What is y in \$9.073 + 0.8 + y = 0.02\$?

A

-9.853.

B

-8.853.

C

-7.853.

D

-10.853.

Soln.
Ans: a

y = 0.02 - (0.8 + 9.073) = -9.853.

### Question 3

Which is the smallest?

A

\$0.077^3\$.

B

\$1/0.077\$.

C

\$0.077\$.

D

\$0.077^2\$.

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, \$1/0.077\$ is same as \$0.077^{-1}\$. The three powers of 0.077 given to us are -1, 1, 2 and 3. Out of these 3 is the most positive, so, \$0.077^3\$ is the smallest.

### Question 4

For what value of x would this expression be a perfect square: \$8.88 × 8.88 - x × 8.88 + 0.5 × 0.5\$?

A

1.

B

0.1.

C

0.001.

D

0.01.

Soln.
Ans: a

Comparing the given expression with \$a^2 - 2 × a ×b + b^2 = (a - b)^2\$, we see that if a = 8.88, and b = 0.5 then by inspection, x should be equal to 2b = 2 × 0.5 = 1.

### Question 5

What is \$14{21/100000}\$?

A

14.00021.

B

14.0021.

C

14.021.

D

1.4021.

Soln.
Ans: a

The given expression can be written as \${14 × 100000 + 21}/100000\$ which is same as \$1400021/100000\$ which gives 14.00021