What will be the ratio of a number obtained by taking the following two steps alternatively in a number and
the number itself
1) Number is decreased by 20 %
2) Number is increased by 20 %
The ranges in which first scheme is more profitable over second in a call ranging from 0:00 (1 sec.) to 3:20 (201 sec.) is –
0-48, 60-98, 120-148, 180-198,
Hence total seconds in which first scheme is more profitable over second are 136.
Therefore probability that first scheme is more profitable over second in a call ranging
from 0:00 (1 sec.) to 3:20 (201 sec.) is 136/201.
Rahim got 12 & 1/4 dozen T-shirts in 12 % discount to printed price and he sold two third of
these T-shirts in 19 % profit to printed price, then he sold other T-shirts in printed price.
If his overall profit is 3626 rupee then printed price of the T-shirt is
Let the printed price of the T-shirt is x, then according to given condition
1.19 x * 2/3 (147) + x * 1/3 (147) – 0.88 x *(147) = 3626
On solving this equation, we get x= 100
A bag contains 6 black and 8 red balls. A ball is drawn at random from the bag. If the ball drawn is black, a coin is tossed twice otherwise no coin is tossed. What is the probability to get two heads respectively on the coins.
Probability of drawing a black ball is 6/14 = 3/7
After then the probability of getting two successive heads is 1/2 * 1/2 = 1/4
Net probability = 3/7 * 1/4 = 3/28
Two trains A and B are moving in opposite direction in different tracks. The length of these trains are 100 m.
and 110 m. respectively. If speeds of A and B are in the ratio 4:5 and these two trains cross each other in 10 sec.
Then speed of train B is
OPtion
1) 70/3 m/s
2) 5/3 m/s
3) 50/9 m/s
4) 55/3 m/s
5) 35/3 m/s
6) 28/3 m/s
7) 4/3 m/s
8) 40/9 m/s
9) 84 m/s
10) 105 m/s
Solution
Let the speeds of the trains are 4v and 5v. Since the trains are moving in opposite direction,
relative speed of the train is 4v + 5v = 9v
According to the formula
speed = distance / time
9v = 210/10 = 21
or v = 7/3 hence speed of B is 5v = 5*7/3 = 35/3 m/s
Ram invests a sum of 8 lacs in two different businesses partly. In first business, he receives a profit of 3.5
lacs and in second business, he obtains a loss of 16 %. In overall business he obtains a profit of
40 %. The ratio of investments in first and second business is
Let the investments in two businesses are respectively x & y
Then according to given conditions
x + 350000 + y × 0.84 = 1.4 (x + y) (i)
x + y = 800000 (ii)
On solving these two equations , we get x = 612500 and y = 187500
Marks of Physics are printed in reverse order in the mark sheet of Surjeet. If printed marks are
less than the correct marks and he gets 67 % after this mistake then which % out of these options is
incorrect for the correct mark sheet (It is given that Surjeet gets success either according to
mark sheet obtained or according to corrected mark sheet. Total marks of the examination are 500)