1. Напишите программу, которая с цикла whіlе находит произведение всех цифр заданного числа

 # Код на ruby 2.2.3p173
a1, a2 = [], []
for i in 100..999
    t = i
    s = 0
    while t>0
        s += t % 10
        t = t / 10
    end

    a1<<i if i%7==0 and s%7==0
    a2<<i if i%47==43
end

p a1
p a2

a3 = []
sum = 0

for i in 31..99
    if i%3==0 and (i%10==2 or i%10==4 or i%10==8)
        a3<<i
        sum += i
    end
end

p sum
p a3

Вывод
[133, 266, 322, 329, 392, 399, 455, 511, 518, 581, 588, 644, 700, 707, 770, 777, 833, 966]
[137, 184, 231, 278, 325, 372, 419, 466, 513, 560, 607, 654, 701, 748, 795, 842, 889, 936, 983]
378
[42, 48, 54, 72, 78, 84]

 # Код на ruby 2.2.3p173
a1, a2 = [], []
for i in 100..999
    t = i
    s = 0
    while t>0
        s += t % 10
        t = t / 10
    end

    a1<<i if i%7==0 and s%7==0
    a2<<i if i%47==43
end

p a1
p a2

a3 = []
sum = 0

for i in 31..99
    if i%3==0 and (i%10==2 or i%10==4 or i%10==8)
        a3<<i
        sum += i
    end
end

p sum
p a3

Вывод
[133, 266, 322, 329, 392, 399, 455, 511, 518, 581, 588, 644, 700, 707, 770, 777, 833, 966]
[137, 184, 231, 278, 325, 372, 419, 466, 513, 560, 607, 654, 701, 748, 795, 842, 889, 936, 983]
378
[42, 48, 54, 72, 78, 84]