For numbers 710-720 there are 4 integers (712,714,716 and 718)
numbers 720-730 there are 3 (724,726,728)
for 730-740 , 750-760, there are 4 in each case.
740-750 , 760-770, 780-790 there are 3 in each case
and for 790-800 there are 4. None for 770-780.
so for numbers 700 - 800 we have a total of 28 integers which fit the requirements.
The number for integers 800 to 900 and 900 to 999 will also be 28 in each case.
Answer is 3*28 = 84 answer.
