# Decimal Numbers Quiz Set 003

### Question 1

What is x in \$0.41/x = 4.1\$?

A

0.1.

B

1.0.

C

0.01.

D

0.001.

Soln.
Ans: a

The expression becomes \$x = {41/41} × {10/100}\$ = 0.1.

### Question 2

What is \${48 × 6.7 - 67 × 8.5}/7.3\$?

A

\$-33{70/73}\$.

B

\$+33{70/73}\$.

C

\$-33{23/73}\$.

D

\$+33{23/73}\$.

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: \${48 × 67 - 67 × 85}/73\$ which equals \${-2479/73}\$, which is same as: \$-33{70/73}\$

### 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

What is \${2.44^2 - 1.86^2}/{2.44 - 1.86}\$?

A

+4.30.

B

+0.58.

C

-4.30.

D

-0.58.

Soln.
Ans: a

We know \$a^2 - b^2\$ = \$(a - b) × (a + b)\$. So \${a^2 - b^2}/{a - b}\$ is same as a + b. We get a + b = 2.44 + 1.86 = 4.30.

### Question 5

What is z in \$9.477 + 0.2 - z = 0.02\$?

A

9.657.

B

8.657.

C

9.756.

D

8.756.

Soln.
Ans: a

z = (0.2 + 9.477) - 0.02 = 9.657. 