the first digit can be any number from 1 to 9 but not 0 (9 options)

the second digit is 2 (1 option)

the third digit can be any number from 0 to 9 (10 options)

the last digit can be 3, 4 or 7 (3 options)

thus there are 9*1*10*3 = 1270 positive four-digit integers have 2 as their second digit and 3, 4, or 7 as their last digit.

the first digit can be any number from 1 to 9 but not 0 (9 options)

the second digit is 2 (1 option)

the third digit can be any number from 0 to 9 (10 options)

the last digit can be 3, 4 or 7 (3 options)

thus there are 9*1*10*3 = 270 positive four-digit integers have 2 as their second digit and 3, 4, or 7 as their last digit.