Ans 1. suppose that the person buys x kg of oil for Rs 252 before the fall in price.After the fall in price he can buy x + 18 kg of oil for Rs 252.

Ans 2.All the numbers from 200 to 299 with 2. Thus, there are 100 such numbers.In addition to this , numbers like 102, 112, 122, …., 192 end with 2. There are 10 such numbers.
Required number = 100 + 10 = 110
Ans 3. Let the corresponding altitudes be h1, h2, and h3,
Now area of the triangle taking the different sides bases separately would be the same .
Required number = 100 + 10 = 110
Ans 3. Let the corresponding altitudes be h1, h2, and h3,
Now area of the triangle taking the different sides bases separately would be the same .

Ans 4. The required sum is : 12 + 15 + 18 +……+ 99 which Is the sum of an A.P. whose first term is 12 ,last term is 99 and common difference is 3.
. . 12 + ( n -1) 3 = 99 => n = 30
Hence, the sum is : 30/2 ( 12 + 99) = 1665.
Ans5. Let x be the price of a mango and y be the price of an orange.
5x + 10 y = 40; x = 2y
. . 10y + 10y= 40 or y =2
Hence, the price of an orange.
Ans 6. The rates at which the three machine A, B, and C work are in the ratio 1 : 2 : 3.
If A can can produce 1 million units in 60 hours, A , B and C together can produce the same number of units in 60 / 1 + 2+ 3 i.e. 10 hours.
. . 12 + ( n -1) 3 = 99 => n = 30
Hence, the sum is : 30/2 ( 12 + 99) = 1665.
Ans5. Let x be the price of a mango and y be the price of an orange.
5x + 10 y = 40; x = 2y
. . 10y + 10y= 40 or y =2
Hence, the price of an orange.
Ans 6. The rates at which the three machine A, B, and C work are in the ratio 1 : 2 : 3.
If A can can produce 1 million units in 60 hours, A , B and C together can produce the same number of units in 60 / 1 + 2+ 3 i.e. 10 hours.
Ans 7.

Ans 8. Let the length the man covers be i.Let the speed of the escalator be x and the speed of the man be y.

Ans 10. N3 – n = ( n – 1) n( n + 1)
Now, (n -1) , n ( n+1) are there consecutive integers, Therefore , one of them should be a multiple of 3 and one at least out of them should be even .Hence, the product ( n – 1) n ( n + 1) should be a multiple of 6.
Now, (n -1) , n ( n+1) are there consecutive integers, Therefore , one of them should be a multiple of 3 and one at least out of them should be even .Hence, the product ( n – 1) n ( n + 1) should be a multiple of 6.
Ans 10.

Ans 11. L.C.M. of 4,6, 7, is 84.
Hence, the required number is 84 + 2 i.e. 86.
Ans 12.

0 Comments