Question Detail

In expressing a length of 81.472 km as nearly as possible with the three significant digits, find the percentage error

0.35%
0.34%
0.034%
0.035%

Answer: Option C

Explanation:

Error = (81.5 - 81.472) = 0.028
Required percentage = \begin{aligned}
\frac{0.028}{81.472} \times 100 = 0.034 %
\end{aligned}

1. 10% of inhabitants of a village having died of cholera, a panic set in, during which 25% of the remaining inhabitants let the village. The population is then reduced to 4050. Find the original inhabitants

5500
6000
6500
7000

Answer: Option B

Explanation:

Let the total number is x,
then,

(100-25)% of (100 - 10)% x = 4050
=> 75% of 90% of x = 4050
=> 75/100 * 90/100 * x = 4050
=> x = (4050*50)/27 = 6000

2. The ratio 5:20 expressed as percent equals to

50 %
125 %
25 %
None of above

Answer: Option C

Explanation:

Actually it means 5 is what percent of 20, which can be calculated as,
(5/20)*100 = 5 * 5 = 25

3. An inspector rejects 0.08% of the meters as defective, How many meters he examine to reject 2 meteres

1200
2400
1400
2500

Answer: Option D

Explanation:

It means that 0.08% of x = 2
\begin{aligned}
=> ( \frac{8}{100 \times 100} \times x) = 2 \\
=> x = \frac{2 \times 100 \times 100}{8} \\
=> x = 2500
\end{aligned}

4. Evaluate 28% of 450 + 45% of 280

Answer: Option C

Explanation:

= (28/100) * 450 + (45/100) * 280
= 126 + 126 = 252

5. A batsman scored 120 runs which included 3 boundaries and 8 sixes. What percent of his total score did he make by running between the wickets.

Answer: Option B

Explanation:

Number of runs made by running = 110 - (3 x 4 + 8 x 6)
= 120 - (60)
= 60

Now, we need to calculate 60 is what percent of 120.

=> 60/120 * 100 = 50 %