Train A leaves kolkata at 8am and is travelling at a speed of 70 km/hr, 4 hours later another train B leaves kolkata and is travelling in same direction as train A in how many time (in minutes) train B will be 25 km ahead train A, if speed of train B is 100 km/hr ?
475 minutes
610 minutes
340 minutes
620 minutes
368 minutes
Option B Distance covered by train A in 4 hours = 70 * 4 = 280 km total distance should be covered by train B from kolkata for ahead 25 km to train A required time = 280 + 25/100-70 = 305/30 * 60 = 610 minutes
In a box there are 3 red balls, 7 white balls and 5 orange balls. If one bottle is drawn at random from the cartoon what is the probability that it is either red balls or white balls ?
2/7
8/9
3/4
5/7
2/3
Option E probability = (3C1) + (7C1)/15C1 = (3 + 7)/15 = 2/3
Two persons A and B alone can do a piece of work in 10 days and 12 days respectively. A and B together worked for 4 days and remaining worked by C alone. If efficiency of C is 20% less than the efficiency of B then find in how many days total work will be completed ?
5 days
8 days
7 days
12 days
6 days
Option B LCM of 10 and 12 = 60 efficiency of A = 60/10 = 6 efficiency of B = 60/12 = 5 work completed by A and B together in 4 days = (6 + 5)* 4 = 44 work remaining work = 60 – 44 = 16 work efficiency of C = 5 * 80/100 = 4 time required to complete the work = 16/4 = 4 work total time to complete the work = 4 + 4 = 8 days
a and B invested rs.2500 and rs.3100 in a business respectively. After 6 months A left the business and C joined with a capital of rs.2200. At the end of 1.5 years the profit received by A and B together is how much percent more or less than that by C ?
125 3/8%
140 10/11%
48 3/5%
152 3/7%
215 3/8%
Option B Profit sharing ratio of A , B and C = (2500 * 1.5) : (3100 * .5) : (2200 * 1) = 75 : 31 : 44 more % = (75 + 31) – 44/44 * 100 = 140 10/11%
Sudha is travelling from point A to B which is 560 km apart with a certain speed. While returning he covers half the distance with 30% less speed than the usual speed and cover the remaining distance with a speed of 140 km/hr. If time taken in both cases is equal, then find the speed of Sudha while going from point A to B ?
75 km/hr
80 km/hr
72 km/hr
84 km/hr
108 km/hr
Option B Let speed of Sudha while travelling from point A to point B = 10x km/hr time taken by Sudha while travelling from A to B = 560/10x time taken by Sudha while returning = 280/7x + 280/140 560/10x = 280/7x + 2 56/x – 40/x = 2 x = 8 speed of Sudha = 10 * 8 = 80 km/hr
Directions : What will come in place of questions (?) marks in the following questions below ? (15)^2 – (18)^2 + 312 = ? + 47
