Can You Pass This Difficult IQ Test From 1987?

8 / 10. PASSED! 2 better than last time!

10 of 10. It took some thought, but wasn't really that difficult.

10/10 correct. Thanks for answers but for a quiz of this type providing an explanation for the logic which determines the correct answer would be helpful.

10/10...passed ...great quiz with answers...thanks for that...

6 / 10. PASSED! I should have done better!

Good quiz, made even more valuable by including the answers. Thanks.

Bernie McGawley, the differences between the numbers are called triangular numbers (1, 3, 6, 10 and 15). If you think of triangles made up of dots, the increase in the numeric interval represents the bottom line of the new triangle.

Great that the answers were shown. Good job.

8/10 quite pleased with result.

Tom Knox, February. Months of the year.

Isabel Weinberg, Didn't see any explanation for #10 (last Q.)

9/10 Missed the last one. Couldn't figure it out.

8/10 missed the two maths question which made sense when I saw the answer - silly me! Thank you for answers

Not a good score today, foggy brain power.

Last 3 questions didn’t display!