95
92
To find the number of ducks in the zoo, we use the given information: There are 160 heads and 450 legs. Let the number of ducks be \(d\) and the number of rabbits be \(r\). Since each duck and rabbit has one head, we have the equation:
\(d + r = 160\)
Each duck has 2 legs and each rabbit has 4 legs. Thus, the second equation is:
\(2d + 4r = 450\)
We can simplify the second equation by dividing it by 2:
\(d + 2r = 225\)
Now, we have the system of equations:
\(1. \quad d + r = 160\)
\(2. \quad d + 2r = 225\)
Subtract equation 1 from equation 2:
\((d + 2r) - (d + r) = 225 - 160\)
\(r = 65\)
Substitute \(r = 65\) back into equation 1:
\(d + 65 = 160\)
\(d = 160 - 65\)
\(d = 95\)
Therefore, the number of ducks in the zoo is 95.
In the given question, a statement is given followed by some conclusions. Choose the conclusion(s) which logically follow(s) the given statement.
Statement: Few shops on this road have neon lights, but they all have signboards.
Conclusions:
I. Some shops have either signboards.
II. Some shops have no signboards.
III. Some shops have no neon lights.
IV. Some shops have both signboards and neon lights.
Select the statements that are CORRECT regarding patterns of biodiversity.
Which of the following hormone is not produced by placenta ?
List - I | List - II | ||
| A | Streptokinase | I | Blood-Cholestrol lowering agents |
| B | Cyclosporin | II | Clot Buster |
| C | Statins | III | Propionibacterium sharmanii |
| D | Swiss Cheese | IV | Immuno suppressive agent |
Which of the following option determines percolation and water holding capacity of soils ?