Exams

Let A’s investment be= 7a
Let B’s investment be= 6a
Let C’s investment be= 5a
Their investment in 2ndyear:= (125% of 7a): (120% of 6a) : (115% of 5a) = 175 : 144 : 115

Gear Lapping is an operation after heat treatment. Gear lapping is the process of imparting a very fine finish and high degree of accuracy to gear teeth, by using a lapping tool and applying a fine-grained abrasive between a work material and a closely fitting surface, called a lapping plate.

A can complete the work in 12 days working 8 hours a day

=> Number of hours A can complete the work = 12×8 = 96 hours 

=> Work done by A in 1 hour = 1/96

B can complete the work in 8 days working 10 hours a day

=> Number of hours B can complete the work = 8×10 = 80 hours 

=> Work done by B in 1 hour = 1/80

Work done by A and B in 1 hour = 1/96 + 1/80 = 11/480

 => A and B can complete the work in 480/11 hours

A and B works 8 hours a day.

Hence total days to complete the work with A and B working together 

= (480/11)/ (8) = 60/11 days

Given in the question that, there are 7 boys and 6 girls. 

Team members = 5

Now, required number of ways in which a team of 5 having atleast 3 girls in the team = 

$$\begin{gathered} 6C3 x 7C2 + 6C4 x 7C1 + 6C5 \\ = 6x5x43x2x1 x 7x62x1 + 6x5x4x34x3x2x1 x 7 + 6x5x4x3x25x4x3x2x1 \\ = 420 + 105 + 6 \\ = 531. \end{gathered}$$

Stratification as actually the settling down of sediments with different properties to form layers/strata over years. Stratification especially occurs on the bed of water bodies such as oceans.

Stratified sedimentary rocks are used to study the ecological conditions over previous years/eras.  

The other choices like Windstorms, Glacial Ice and Stream water are mediums which sediments are transported.

For exampe if it is 12:45 AM, then after 8 hours the time is 

12 hrs 45 min + 8 hrs = 8 : 45 PM in the night on the same day.