# Decimal Numbers Quiz Set 005

### Question 1

What is \${4.91^3 - 0.40^3}/{4.91^2 + 1.964 + 0.40^2}\$?

A

+4.51.

B

+5.31.

C

-5.31.

D

-4.51.

Soln.
Ans: a

We know \${a^3 - b^3}/{a^2 + ab + b^2}\$ is same as \${(a - b) × (a^2 + ab + b^2)}/{a^2 + ab + b^2}\$ which is same as a - b. So we get a - b = 4.91 - 0.40 = 4.51.

### Question 2

What is \$0.013896/0.02\$?

A

0.6948.

B

6.948.

C

0.06948.

D

0.006948.

Soln.
Ans: a

The given expression can be written as \${13896/2} × {100/1000000}\$ which is same as \${13896/2} × {1/10000}\$, which is same as \$6948 × {1/10000}\$, which is same as 0.6948

### Question 3

If \$2.35/0.3\$ = 7.833333, then \$0.0235/3\$ = ?

A

0.007833333.

B

0.07833333.

C

0.7833333.

D

0.0007833333.

Soln.
Ans: a

Numerator is divided by 100, and denominator multiplied by 10, so the answer should get divided by 1000.

### Question 4

What is \$6.062 - (-0.8) + 0.03 - (-0.09)\$?

A

6.982.

B

7.982.

C

5.982.

D

8.982.

Soln.
Ans: a

The given expression is same as \$6.062 + 0.8 + 0.03 + 0.09\$, then by simple addition we get \$6.062 + 0.8 + 0.03 + 0.09 = 6.982\$.

### Question 5

What is \${0.60 × 0.60 × 0.60 + 0.04 × 0.04 × 0.04}/{4.80 × 4.80 × 4.80 + 0.32 × 0.32 × 0.32}\$?

A

\$1/8^3\$.

B

\$1/8^2\$.

C

\$1/7^3\$.

D

\$1/7^2\$.

Soln.
Ans: a

By inspection, the given ratio is same as \${0.60 × 0.60 × 0.60 + 0.04 × 0.04 × 0.04}/{8^3 × ({0.60 × 0.60 × 0.60 + 0.04 × 0.04 × 0.04})}\$ which is \$1/8^3\$.