A grocery clerk sets up a display of 12-pack cartons of cola. There are 15 cartons at the base of the triangle and one at the top. How many cartons of
cola are needed for the complete display?

120 cartons

Step-by-step explanation: Since, the grocery clerk displays 15 cartons at the base of the triangle and one at the top. Therefore, one carton is reduced at previous step and so on. Since, this series is in arithmetic progression. Therefore, 120 cartons are needed for the complete display.

the mistake in the pattern is that :

b. the decimal point was moved one too many place values each time

the correct pattern could be made by :

b. moving the decimal point to the right the same numbers of place values as the exponents

answer: all of the odd numbers were opened

the first person was the one that was opening all of the lockers. since one is odd, this causes all of the odd number lockers to be opened in the end.