2. How many litres of pure acid are there in 8 litres of a 20% solution
1.5
1.6
1.7
1.8
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
3. Total number of boys and girls in a school is 150. If the number of boys is x, then girls become x% of the total number of students. The number of boys is
50
60
70
80
Answer: Option B
Explanation:
Clearly,
x% of 150 = 150 - x [as x is number of boys]
\begin{aligned}
=> x + \frac{x}{100} * 150 = 150 \\
=> \frac{5}{2}x = 150 \\
=> x = 60 \\
\end{aligned}
4. One fourth of one third of two fifth of a number is 15. What will be40% of that number
140
150
180
200
Answer: Option C
Explanation:
(1/4) * (1/3) * (2/5) * x = 15 then x = 15 * 30 = 450
40% of 450 = 180
5. 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