Question

If the pattern below follows the rule "Starting with four, every consecutive line has a number one more than the previous line," how many marbles must be in the seventh line?

Answer 1

7 - 4 (becaause there already is 4 rows) = 3. 

3 x 1 = 3. 

Basically you have to add 3 to the number that is in the 4th row. This should be 10, because 7 + 3 = 10

Answer 2

7+3=10 just add them together