From powerprap 2006, frist question many times help me

[keyur]

(1) IF the grade of Ane was 90 percentile of 80 grade and of 100 grade of other class, 19 higher then Ane‘s and rest of grades is lower then grade of two class combine is what?

ANS-85 th

(2) 58 was 2 standard deviation below mean and 98 was 3 standard deviation below mean, so mean is?

[CTG1983]

Don't understand the wording of the first Qs.
Q2: U wrote the Qs wrong. It should be 98 is 3 SD above the mean.
M-2S=58-------------(i)
M+3S=98---------------(ii)

Solve these equations, u will get the ans. M stands for mean and S for Std. Deviation.

Q1:
90%*80=72
100-19=81
Total=72+81=153
percentile=153/180=85%

[keyur]

Thank a lots, nice logic

actully this both que.comes many times as a first qus in GMATprep .