1.
In expressing a length of 81.472 km as nearly as possible with the three significant digits, find the percentage error
Answer: Option 'C'
Error = (81.5 - 81.472) = 0.028
Required percentage = (0.028/81.472) x 100 = 0.034%
2.
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
Answer: Option 'B'
x% of 150 = 150 - x [as x is number of boys]
=> x + (x/100) × 150 = 150
=> (5/2)x = 150
=> x = 60
3.
Three candidates contested an election and received 1136, 7636 and 11628 votes respectively. What percentage of the total votes did the winning candidate got
Answer: Option 'C'
Total number of votes polled = (1136 + 7636 + 11628) = 20400
So, Required percentage = 11628/20400 * 100 = 57%
4.
Half of 1 percent written as decimal is
Answer: Option 'D'
It will be 1/2(1%) = 1/2(1/100) = 1/200 = 0.005
5.
If the radius of a circle is increased by 50%, its area is increased by
Answer: Option 'A'
125%