We can find the number of terms in a geometric progression by using the formula:
Number of terms = (logarithm of the last term over the first term) / (logarithm of the common ratio + 1)
In this case, the first term is 2, the last term is 128, and the common ratio is 4/2 = 2.
So,
Number of terms = (log 128 / log 2) / (log 2 + 1)
Number of terms = (7 / 1) / (1.301 + 1)
Number of terms = 7 / 2.301
Number of terms = 3.036
Therefore, there are approximately 3 terms in the geometric progression 2, 4, 8...,128.