Which element is common in both hemoglobin and myoglobin?

Which of the following is an example of a neutral oxide?

Let $f(0)=1, f(0.5)=\frac{5}{4}, f(1)=2, f(1.5)=\frac{13}{4}$ and $f(2)=5$. Using Simpson's rule,$\int_0^2 f(x) dx$ is equal to

Which one of the following orders presents the correct sequence of the increasing basic nature of the given oxides?

$A$ bi-convex lens is formed with two thin plano-convex lenses as shown in the figure. The refractive index of the first lens is $1.5$ and that of the second lens is $1.2$. Both the curved surfaces have the same radius of curvature $R = 14\; cm$. For this bi-convex lens,if the object distance is $40\; cm$,the image distance will be: (in $; cm$)