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

Answer: Option C

Explanation:

Let the third number is x.
then first number = (100-30)% of x
= 70% of x = 7x/10

Second number is (63x/100)

Difference = 7x/10 - 63x/100 = 7x/10

So required percentage is, difference is what percent of first number

=> (7x/100 * 10/7x * 100 )% = 10%

Answer: Option B

Explanation:

Question of this type looks a bit typical, but it is too simple, as below...

It will be 8 * 20/100 = 1.6

Answer: Option A

Explanation:

Let the original price per egg be Rs x
Then increased price will be,
\begin{aligned}
\left(\frac{130}{100}x\right) \\
=> \frac{7.80}{x}-\frac{7.80}{\frac{130}{100}x} = 3\\
=> \frac{7.80}{x}-\frac{780}{130x} = 3 \\
=> 390x = 234 \\
=> x = 0.6 \\

\text{Actual price was Rs 0.6} \\
\text{Present price per dozen will be} \\
Rs.\left(12*\frac{130}{100}*0.6 \right) \\
= Rs. 9.36
\end{aligned}

Answer: Option A

Explanation:

Actual Price = Rs.25 + Rs.2.50 = Rs.27.5

Saving = Rs.2.5

\begin{aligned}\text{Percentage Saving = }\dfrac{2.5}{27.5}\times 100 \\
= \dfrac{250}{27.5} = \dfrac{2500}{275}\\
= \dfrac{100}{11} = 9\dfrac{1}{11}\% \approx 9\%\end{aligned}

Answer: Option C

Explanation:

(1/4) * (1/3) * (2/5) * x = 15 then x = 15 * 30 = 450
40% of 450 = 180