Ques 1.
The sum of three numbers is 280. If the ratio of the first number to the second is 1 : 3 and that of the second to the third is 9 : 16, what is the sum of the second and the third number ?
Solution :
Try to equal common number
==>1:3 *3 = 3: 9
==>9:16 *1 = 9:16
Ratio of three numbers = 3:9:16
Sum of 2nd and 3rd numbers = 25*280/28 = 250
Ques 2.
Two stations A and B are 220 km apart on a straight track. One train starts from A at 7 a.m. and travels towards B at 40 kmph. Another train starts from B at 8 a.m. and travels towards A at a speed of 50 kmph. At what time will they meet?
Solution :
40x + 50(x-1) = 220
==> 40x+50x-50 = 220
==> 90x = 270
==> X = 3 Hrs
Time of meeting = 7+3 = 10 A.M
Ques 3.
A bag contains 25p coins, 50p coins and 1 rupee coins whose values are in the ratio of 8:4:2. The total values of coins are 420. Then find the total amount in rupees.
Solution :
Value is given in the ratio 8:4:2.
(8x/0.25) + (4x/0.5) + (2x/1) = 420.
X = 10.
(8x/0.25) + (4x/0.5) + (2x/1) = 420.
X = 10.
Total amount = 14*10 = 140
Ques 4.
Ravi bought 20 tables at the rate of 100 each. She spends 1600 rupees on transportation and 400 on packaging. At what price should Ravi sell a table to make a profit of 20%.
Solution :
Total cost = 600*20 + 1600 + 400 = 14000
CP of one table = 14000/20 = 700.SP = 700*120/100 = 840
Ques 5.
A card is drawn from a pack of 52 cards. The card is drawn at random; find the probability that it is neither club nor queen?
Solution :
1 – [13/52 + 4/52 – 1/52] = 9/13
Ques 6.
Two pipes A and B can fill a cistern in 12 hours and 4 hours respectively. If they are opened on alternate hours and if pipe A is opened first, in how many hours will the tank be full?
Solution :
Pipe P can fill = 1/12
Pipe Q can fill = 1/4
For every two hour, 1/12 + 1/4 = 1/3
Total = 6 hours
Pipe Q can fill = 1/4
For every two hour, 1/12 + 1/4 = 1/3
Total = 6 hours
Ques 7.
The population of a city has increased annually at the rate of 10%. If at the end of 3 years it is 133100, the population in the beginning of the first year?
Solution :
==> X *(110*110*110)/(100*100*100) = 133100
==> X = 100000
Ques 8.
A, B, C invested in the ratio of 6:5:7. After the end of business term they receive the profit in the ratio 3:1:5. Find the ratio of time in which they invested in the business.
Solution :
Times Ratio = 3/6 : 1/5 : 5/7
= 105 : 42 : 150
= 35 : 14 : 50
Ques 9.
3 4 10 32 136 685 4116 . Find wrong number out ?
Solution :
3 * 1 + 1 = 4
4 * 2 + 2 = 10
10 * 3 + 3 = 33
4 * 2 + 2 = 10
10 * 3 + 3 = 33
Ques 10.
3x2 – 4x – 4 = 0, 4y2 + 23y + 15 = 0
Solution :
3x2 – 4x – 4 = 0
3x2 + 2x – 6x – 4 = 0
x = -2/3 , 2
3x2 + 2x – 6x – 4 = 0
x = -2/3 , 2
4y2 + 23y + 15 = 0
4y2 + 20y + 3y + 15 = 0
y = -5, -3/4
X > Y