Quantitative Aptitude Topics

(Number System, Percentage, Partnership)

Number System

1. A number is divisible by 2, if its unit’s place digit is 0, 2, 4, or 8
2. A number is divisible by 3, if the sum of its digits is divisible by 3
3. A number is divisible by 4, if the number formed by its last two digits is divisible by 4
4. A number is divisible by 8, if the number formed by its last three digits is divisible by 8
5. A number is divisible by 9, if the sum of its digits is divisible by 9
6. A number is divisible by 11, if, starting from the RHS,
(Sum of its digits at the odd place) – (Sum of its digits at even place) is equal to 0 or 11x

Percentage

1.To express x% as a fraction, we have x% = x / 100
2. To express a / b as a percent, we have a / b = (a / b × 100) %
3. If ‘A’ is R% more than ‘B’, then ‘B’ is less than ‘A’ by
OR
If the price of a commodity increases by R%, then the reduction in consumption, not
to increase the expenditure is
{100R / [100 + R] } %
4. If ‘A’ is R% less than ‘B’, then ‘B’ is more than ‘A’ by
OR
If the price of a commodity decreases by R%, then the increase in consumption, not to
increase the expenditure is
{100R / [100 - R] } %
5. If the population of a town is ‘P’ in a year, then its population after ‘N’ years is
P (1 + R/100)N
6. If the population of a town is ‘P’ in a year, then its

P / [(1 + R/100)N

Partnership

1. If a number of partners have invested in a business and it has a profit, then
Share Of Partner = (Total_Profit × Part_Share / Total_Share)