In only 50 years, the world's consumption of raw materials has nearly quadrupled, to more than 100 billion tons. Less than $9 \%$ of this is reused. Batteries of old vehicles contain materials such as lithium, cobalt, manganese and nickel that are pricey and can be hard to obtain. Supply chains are long and complicated. Buyers' risks are being aggravated by their suppliers' poor environmental and labour standards. Reusing materials makes sense. Once batteries reach the ends of their lives, they should go back to a factory where their ingredients can be recovered and put into new batteries.

If $n$ is a natural number, then what is the number of distinct remainders of $\left(1^n+2^n\right)$ when divided by 4 ?

In only 50 years, the world's consumption of raw materials has nearly quadrupled, to more than 100 billion tons. Less than $9 \%$ of this is reused. Batteries of old vehicles contain materials such as lithium, cobalt, manganese and nickel that are pricey and can be hard to obtain. Supply chains are long and complicated. Buyers' risks are being aggravated by their suppliers' poor environmental and labour standards. Reusing materials makes sense. Once batteries reach the ends of their lives, they should go back to a factory where their ingredients can be recovered and put into new batteries.

What is the 489 th digit in the number $123456789101112 \ldots$ ?

"A good statesman, like any other sensible human being, learns more from his opponents than from his fervent supporters. For his supporters will push him to disaster unless his opponents show him where the dangers are. So if he is wise he will often pray to be delivered from his friends, because they will ruin him. But, though it hurts, he ought also to pray never to be left without opponents; for they keep him on the path of reason and good sense. The national unity of free people depends upon a sufficiently even balance of political power to make it impracticable for the administration to be arbitrary and for opposition to be revolutionary and irreconcilable."

The 5-digit number PQRST (all distinct digits) is such that $\mathbf{T} \neq \mathbf{0} . \mathbf{P}$ is thrice $\mathbf{T} . \mathbf{S}$ is greater than $\mathbf{Q}$ by 4, while $Q$ is greater than $R$ by 3 . How many such 5-digit numbers are possible?

"A network of voluntary associations stands as a 'buffer' between the relatively powerless individual and the potentially powerful State."

Consider the following statements:

I. There exists a natural number which when increased by $50 \%$ can have its number of factors unchanged.

II. There exists a natural number which when increased by $150 \%$ can have its number of factors unchanged.

Which of the statements given above is/are correct?