Aptitude Questions

1) A bag contains 90 tokens numbered serially from 0 to 89. If N is the no. of ways of selecting 3 tokens without replacement such that the sum of the no. on them is 90, then N is divisible by….. 2)the of all possible selections which a student can make for answering one or more questions out of 8 given in a paper,when each ques has an alternative.(3^8 -1). 3)the probability of getting a sum of 12 in a 4 throws of an ordinary dice. 4)out of agroup of 20 teachers in a school,10 teach maths,9 physics,7 chem,4 both maths&phy,but none teach both maths & chem..the no. of teachers who teaches both chem.&phy? 5)the letters of the word ‘BAZAR’ are arranged in dictionary, then wht is the 50th word?(ZAARB). 6)a fair coin is tossed a fixed no. of times.If the probability of getting 7 heads=that of getting 9 heads ,the prob. Of getting 2 heads? 7)a new sequence is obtained from the sequence of positive integers{1,2,3,……} by deleting all perfect squares . then the 2003rd term? 8)a workman earned Rs 180 in a certain no. of days. If his daily wages had been Rs2 less,he would take1 more day to earn the same amount. Find how many days he would have worked at the higher rate?(9) 9)divide Rs 671 among A,B,C such that if their shares be increased by Rs 3,7,9 respt,the result shall be in the ratio of 1:2:3? 10)there are 2 alloys of silver and copper .in the first there is 3 times as much Cu as Ag and in the 2nd there is ¼ th as much Cu as Ag.how many times more \must we take the 1st alloy in relation to the 2nd in order to obtain a new alloy in which there would be twice as much Cu as Ag? 11)a cup of milk contains 3 parts of pure milk & 1 part of water.how much micture must be withdrawn and water substituted in order that the resulting mix may be half milk & half water? 12)a man ,a woman or a boy can do a job in 3,4,or 12 days respt. How many boys must assist 1 man and 1 woman to do the job in 1 and half day? 13) a cistern has 3 pipes A,B,C. the pipes A ,B can fill it in 4,5 hrs and C can empty it in 2 hrs .if the pipes are opened in order at 1,2 and 3 am rest,when will the cistern be empty?

14)2 workers A,B manufactured a batch of identical parts.A worked for 2 hrs ,B for 5 hrs and did half the job. Then they worked for 3 hrs and they had 1/20 th of the job.how much time does B take to complete the job,if he worked alone? 15)ram starts working on a job and works on it for 12 days and completes 40% of the work. To help him complete the work,he employs ravi and the together they work for another 12 days and finishes the work.how much more efficient is ram than ravi? 16)there are benches in a classroom .if 4 students sit on on each bench,3 benches are vacant and if 3 students sit on eaxch bench,3 studentas are left standing.the total no. of students in the class? 17)sandhya was married 6 yrs ago.her present age is 5/4 th times of marriage.her daughters age is 1/6th of her age.if sandhya was married in 1996 ,then her daughter was born in ? 18)4 persons agree with a 5th parson T to collect a certain sum.they subscribe Rs 150 each and T is to pay Rs40 more more than the avg.of all the 5.find the sum.? 19)from a group of officers and assistants,15 assistants leave.then 2 officers are left for each assistant.after this,45 officers leave.there are then 5 assistants for each officer.find the no of assistants in thje beginning?