ব্যাংক জব নিয়োগ পরীক্ষা গণিত Ratio

ব্যাংক জব নিয়োগ পরীক্ষা গণিত Ratio

What is Ratio?
A ratio is a relationship between two numbers by division of the same kind. The ration of a to b is written as a : b = a / b In ratio a : b , we can say that a as the first term or antecedent and b, the second term or consequent.

Example :  The ratio 4 : 9 we can represent as  4 / 9 after this 4 is a antecedent and , consequent = 9

Rule of ration :  In ratio multiplication or division of each an every term of a ratio by the same non- zero number does not affect the ratio.

What is Proportion?
The idea of proportions is that two ratio are equal.
If a : b = c : d, we write a : b : : c : d,
Ex. 3 / 15 = 1 / 5
a and d called extremes, where as b and c called mean terms.

Proportion of quantities
the four quantities a, b, c, d said proportion then we can express it
a : b = c : d
Then a : b : : c : d  <–> ( a x d ) = ( b x c )
product of means = product of extremes.

If there is given three quantities like a, b, c of same kind then then we can say it proportion of continued.
a : b = b : c the middle number b is called mean proportion. a and c are called extreme numbers.
So, b² = ac. ( middle number )² = ( First number x Last number ).

Example 1:
If P : Q : R = 2 : 3 : 4 , Then P / Q : Q / R : R / P = ?
Answer :
P : Q : R = 2 : 3 : 4 . Let P = 2k, Q = 3k, R = 4k. Then,
P / Q = 2k / 3k = 2 / 3 , Q / R = 3k / 4k = 3 / 4 and R / P = 4k / 2k = 2 / 1.

SO, P / Q : Q / R : R / P = 2 / 3 : 3 / 4 : 2 / 1 = 8 : 9 : 24 .

Example 2:
If 2P = 3Q = 4R, Then P : Q : R = ?
Answer :
Let 2P = 3Q = 4R = k , Then , P = k / 2, Q = k / 3 , R = k / 4.
SO , P : Q : R = k / 2 : k / 3 : k / 4 = 2 : 3 : 4

এই লেকচারের পরের পেইজে যেতে নিচের …. তে ক্লিক কর।