Question

The model of tower shown here is made up of unit cubes stacked on top of each other. How many unit cubes in all are used to form the tower ?

• A. $35$
• B. $36$
• C. $37$
• D. $38$

Answer 1

The correct option is A $35$

Total number of cubes in row $1$= $1$

Total number of cubes in row $2$= $3$

Total number of cubes in row $3$= $6$

Total number of cubes in row $4$= $10$

Total number of cubes in row $5$= $15$

$\therefore$ Total number of cubes= $1+3+6+10+15=35$.