Exams

The pattern is 12 22, 32 42, 52 62, 

∴The next number= 72 82= 4964

Hardness can be removed by adding sodium carbonate (washing soda) or by passing the water through an ion-exchange column.

Hardness in water is caused by dissolved magnesium ions and calcium ions. These can get into the water when it comes into contact with limestone and other rocks that contain calcium compounds. This can happen, for example, when rainwater flows over these rocks on its way to a reservoir.

Hardness in water is of two types. They are :

1. Temporary hardness

2. Permanent hardness

1. Temporary hardness:: Temporary hardness is caused by dissolved calcium hydrogen carbonate.

2. Permanent hardness:: Permanent hardness is caused by dissolved calcium sulfate. Unlike temporary hardness, it is not removed by boiling the water.

ROUTINE IS 7 LETTER WORD.. (1st=R,2nd=O,3rd=U,4th=T,5th=I,6th=N,7th=E)
1st and 3rd letter interchanging. (UORTINE)
5th and 7th letter interchanging. (UORTENI)
1st letter shifting one after that (VORTENI)
2nd letter shifting two befor that (VMRTENI)
3rd letter remains same (VMRTENI)
4th letter
(total alphabets - current)+1
(26 - 20)+1= 7.(i.e) G (VMRGFNI)
5th letter shifting one after that (VMRGFNI)
6th letter shifting two befor that (VMRGFLI)
7th letter remains same (VMRGFLI
Like that,
CRUELTY IS 7 LETTER WORD.. (1st=C,2nd=R,3rd=U,4th=E,5th=L,6th=T,7th=Y)
1st and 3rd letter interchanging. (URCELTY)
5th and 7th letter interchanging. (URCEYTL)
1st letter shifting one after that (VRCEYTL)
2nd letter shifting two befor that (VPCEYTL)
3rd letter remains same (VPCEYTL)
4th letter
(total alphabets - current)+1
(26 - 5)+1= 22.(i.e) V (VPCVYTL)
5th letter shifting one after that (VPCVZTL)
6th letter shifting two befor that (VPCVZRL)
7th letter remains same (VPCVZRL).