31.
Among the 50 students in a class, what percentage of students like biology and chemistry?
Answer : B. 46%
32.
For any n observations of data, what is the value of (∑x) - nx ?
Answer : D. 0
33.
Simplify : 0.728x0.728-0.272x0.272 0.456
Answer : B. 1
34.
If x/y = 3/5, then 5x + 2y is equal to 5x - 2y
Answer : B. 5
35.
A person's present age is two-fifth of the age of his mother. After 8 years, he will be one half of his mother at present?
Answer : B. 40
36.
Find the value of 1.2x1.2x1.2-0.2x0.2x0.2 1.2x1.2+1.2x0.2+0.2x0.2
37.
A bicycle marked at Rs. 1,500 is sold for Rs. 1,350. What is the percentage of discount?
Answer : D. 10
38.
Which one of the following is the smallest ratio? 7 : 3, 17 : 25, 7 : 15, 15 : 23
Answer : C. 7:15
39.
In a mixture of 60 litres, the ratio of milk and water is 2 : 1. If this ratio is to be 1 : 2, then what is the quality of water to be further added?
Answer : D. 60 l
40.
Two numbers are in the ratio 3 : 5. If 9 be subtracted from each, then they are in the ratio 12 : 23. Find the second number
Answer : D. 55