The respective ratio of radii of two right circular cylinders (A & B) is 2 : 5. The respective ratio of the heights of cylinders A and B is 3 : 1. What is the respective ratio of volumes of cylinders A and B?
Raja gives 30% of his salary to his mother, 40% of the remaining salary he invests in an insurance scheme and PPF in the respective ratio of 4 : 3 and the remaining he keeps in his bank account. If the difference between the amount he gives to his mother and that he invests in insurance scheme is Rs. 8400, how much is Raja’s salary?
Answer: Option A
Let Raja salary= R
Salary given to mother = 0.3 R
Money left=0.7 R
Now, Money invested in Insurance scheme= 0.7*0.4*4/7 R= 0.16 R
Difference of money in bank and with mother= 0.14R
Now, 0.14 R=8400, Hence R= 60,0000
A, B, C and D are four consecutive odd numbers and their average is 42. What is the product of B and D?
None of these
Answer: Option C
As there are As diff. Is same so average should lie between B and C so B is 41 & C is 43 so D must be 45 as we have to find the product of B and D so it would be 1845.
A basket contains 3 blue, 5 black and 3 red balls. If 2 balls are drawn at random, what is the probability that one is black and one is red?
None of these
Answer: Option D
Selecting 1 black ball out of 5 = 5C1 ways.Selecting on red ball out of 3 = 3C1 ways
The required probability = ( 5C1 × 3C1)/ 11C2 = 3/11
A man buys a land and gives for it 20 times the annual rent Find the rate of interest he gets for his money.
Answer: Option B
Let annual rent is 1 Rs. so buys the land at 20 Rs. So by investing Rs.20 he is getting Rs.1 as interest. so on Rs.100 he gets Rs.5 . so rate%=5%.Hence option E is the answer.