GATE Questions

---

Why Water Is Not an Element :

An element is a substance consisting of only one type of atom. Water consists of two types of atoms: hydrogen and oxygen.

water is both a molecule and a compound :

A compound forms whenever two or more atoms form chemical bonds with each other. The chemical formula for water is H2O, which means each molecule of water consists of one oxygen atom chemically bonded to two hydrogen atoms.

Thus, water is a compound.

It's also a molecule, which is any chemical species formed by two or more atoms chemically bonded to each other. The terms molecule and compound mean the same thing and can be used interchangeably.

Hence, water is both a molecule and a compound.

As given equal amounts of alloys are melted, let it be 1 kg.

Required ratio of gold and silver = 513 + 58813 + 38 = 105103.

Hence, ratio of gold and silver in the resulting alloy = 105/103.

Given 5:6 :: 7:10 :: 6:5

We know that compound ratio is calculated as
a:b :: c:d :: e:f
(axcxe):(bxdxf)

=> (5x7x6):(6x10x5)
=> (210):(300)
= 7:10

Given 30% of 500

$$\begin{gathered} = 30100 x 500 \\ = 30 x 5 \\ = 150 \end{gathered}$$

Hence, 30% of Rs. 500 = Rs. 150.

The twentieth element in the above arrangement is 'E'.
Then, the sixth element to the left of 'E' is 'L'.

Daughter of your mother's father's mother => Maternal grandmother => Renu's Aunt.

Hence, Laxmi is Renu's Aunt and Vishal is Renu's Uncle.

Work done by the third pipe in 1 min = 1/50 - (1/60 + 1/75) = - 1/100.
[-ve sign means emptying]

The third pipe alone can empty the cistern in 100 min.