Question: 41 -

In a factory there are three types of Machines M1 , M2 and M3 which produces 25%, 35% and 40% of the total products respectively. M1, M2 and M3 produces 2% , 4% and 5% defective products, respectively. What is the percentage of non-defective products?

89%

96.1%

97%

86.1%

Answer:

96.1%

Solution:

Non- defective products

{(25x0.98+35x0.96+40x0.95)/100} x 100 = 96.1

Question: 42 -

In measuring the sides of a rectangle errors of 5 % and 3 % in excess are made. The error percent in the calculates area is 

8.15%

8. 35 %

7.15%

6. 25%

Answer:

8.15%

Solution:

Let length = x units and breadth = Y units 
Then actual area = xy sq.units 
Length shown = (105/100 × x)units = 21x/20 units; 
Breadth shown = (103/100 × Y) 
Calculated area = (21x/20 × 103y/100)sq.units 
= 2163xy/2000 sq.units 
Error = (2163xy/2000 - xy) 
= 163xy/2000 
Error % = (163xy/2000 × 1/xy × 100)% 
= 163/20 % = 8.15 % 

Question: 43 -

Fresh grapes contain 80 % water dry grapes contain 10 % water. If the weight of dry grapes is 250 kg. What was its total weight when it was fresh? 

1225kg

1000kg

1125kg

1100kg

Answer:

1125kg

Solution:

Let the weight of fresh grapes be x kg 
Quantity of water in it = (80/100 × x)kg = 4x/5 kg 
Quantity of pulp in it = (x – 4x/5)kg = x/5 kg 
Quantity of water in 250 kg dry grapes 
= (10/100 × 250)kg = 25kg 
Quantity of pulp in it = (250 - 25)kg = 225 kg 
Therefore, x/5 = 225 
=> x = 1125 

Question: 44 -

The average of a set of whole numbers is 27.2. when the 20% of the elements are eliminated from the set of numbers then the average become 34. The number of elements in the new set of numbers can be :

27

63

35

52

Answer:

52

Solution:

only (c) is correct since it is divisible by 4.
Let the original number of element  be x then the new no.of elements will be 
            4x/5 = K                               
So K must be divisible by 4
Since,      x =  Kx5/4