Start here · the first lesson of Table with missing values
Table with missing values
DI: Tables · for IPMAT Indore, IPMAT Rohtak and JIPMAT
Sign in to watch · 5 min video
The idea
A partial table gives a few cells and some sentence conditions (a percentage, a fraction of a group, an average). Every blank can be filled by row and column sums. JIPMAT 2022 Q4-7 gave a 3 x 4 grid of sex by grade with only three cells and three conditions; all four questions read off the completed grid.
Textbook vs exam method
Textbook method
- Write the grid with a total row and a total column.
- Translate each condition into a cell or a total.
- Repeatedly fill any row or column that has exactly one blank.
- Check every sum, then answer.
Exam method
- Grand total first. girls = 40 and 50% are girls, so the total is 80.
- Group fractions. 1/4 of the 40 boys have C = 10.
- Chain. A or B = 40, so C total = 40, girls C = 30; boys B = 40 - 5 - 10 = 25; girls B = 30 - 25 = 5.
- Read all the answers off the finished grid.