Search SchoolNGR

Wednesday, 05 August 2026
Register . Login

Mathematics Past Questions and Answers

Mathematics Questions

Question 286:
Find the unit vector in the direction of \(-2i + 5j\).
  • A \(\frac{1}{\sqrt{29}}(2i + 5j)\)
  • B \(\frac{1}{\sqrt{29}}(-2i + 5j)\)
  • C \(\frac{1}{29}(2i - 5j)\)
  • D \(\frac{1}{29}(-2i - 5j)\)
View Answer & Explanation
Question 287:
Given that \(n = 10\) and \(\sum d^{2} = 20\), calculate the Spearman's rank correlation coefficient.
  • A 0.121
  • B 0.733
  • C 0.879
  • D 0.979
View Answer & Explanation
Question 288:
Find the variance of 11, 12, 13, 14 and 15.
  • A 2
  • B 3
  • C \(\sqrt{2}\)
  • D 13
View Answer & Explanation
Question 289:
A fair coin is tossed 3 times. Find the probability of obtaining exactly 2 heads.
  • A \(\frac{1}{8}\)
  • B \(\frac{3}{8}\)
  • C \(\frac{5}{8}\)
  • D \(\frac{7}{8}\)
View Answer & Explanation
Question 290:
A box contains 14 white balls and 6 black balls. Find the probability of first drawing a black ball and then a white ball without replacement.
  • A 0.21
  • B 0.22
  • C 0.30
  • D 0.70
View Answer & Explanation