Quantitative Aptitude - Arithmetic Ability Questions

In a school there are 1500 students, 44% of them are girls. Monthly fee of each boy is 540 and fee of each girl is 25% less than that of a boy. The sum of fees of boys & girl is

Find the LCM of 0.63, 10.5, 2.1, 4.20

Simple interest on a sum of Rs 1400 for 3 years and 4 months is Rs 700. What is the rate (in percentage) of interest per annum?

If 2/3(6x/5 - 1/4) + 1/3 = 9x/5, then what is the value of x?

If cosec4A -­ cosec2A = x, then value of x is?

Two numbers whose sum is 84 can not be in the ratio

A boy found the answer for the question "Subtract the sum of 1/4 and 1/5 from unity and express the answer in decimals" as 0.45. The percentage of error in his answer was

A student multiplied a number by 3/10 instead of 10/3. What is the percentage error in the calculation?