The student in a hostel was asked whether they had a TV set or a computer in their rooms. The result showed that 650 students had a TV set; 150 did not have a TV set; 175 had a computer and 50 had neither a TV set nor a computer. Find the number of students who live in a hostel, have both a TV set and a computer, and have only a computer. please answer my question it's urgent​

But we pulled at the grill [on the ground] and it gave way. and then we saw iron rings as steps leading down a shaft into a darkness without bottom. … it was a great tunnel. its walls were hard and smooth to the touch; it felt like stone, but it was not stone. on the ground there were long thin tracks of iron, but it was not iron; it felt smooth and cold as glass. we knelt, and we crawled forward, our hand groping along the iron line to see where it would lead. but there was an unbroken night ahead. what is the most likely explanation for the walls described in the bold text?

Rewrite the passage to improve expression.

Metals are good conductors due to the presence of many