same answer here with one small difference in the calculation:
To find for example the multiples of 5 below 2000, we notice the first is 5 and the last is 1995 and there are 399 such numbers. The first + the last = 5 + 1995 = 2000, so is the second + the second last = 10 + 1990 = 2000. This can be repeated 199 times and then we are left with 1000. So the sum is 199 x 2000 + 1000 = 399000.
The same can be done for 7 and 35, and the answer is 626430 as @doughtaker wrote.