PYTHON

sum of all multiples of 3 and 5 below 100

c = list(range(1,100))

total = 0

for i in (c):
    if i % 3 == 0 or i % 5 == 0:
      total += i
print (total)

Sum of all the multiples of 3 or 5

const findSum = n => {
  let countArr = []
  
  for(let i = 0; i <= n; i++) if(i % 3 === 0 || i % 5 === 0) countArr.push(i) 
  return countArr.reduce((acc , curr) => acc + curr)
}
console.log(findSum(5))

// With love @kouqhar

sum of multiples of 5 from 1 to 100

total = 0

for i in range(1, 100):
    if i % 3 == 0:
        total = total + i
print(total)

total1 = 0
for i in range(1, 100):
    if i % 5 == 0:
        total1 = total1 + i
print(total1)