Анонимно

Сочетание. Сколько раз встречается сочетание 42 в записи чисел
от 1 до 10 000?

Ответ

Анонимно

42, 142, 242, 342, 420, 421, 422, 423, 424, 425, 426, 427, 428, 429, 442, 542, 642, 742, 842, 942, 1042, 1142, 1242, 1342, 1420, 1421, 1422, 1423, 1424, 1425, 1426, 1427, 1428, 1429, 1442, 1542, 1642, 1742, 1842, 1942, 2042, 2142, 2242, 2342, 2420, 2421, 2422, 2423, 2424, 2425, 2426, 2427, 2428, 2429, 2442, 2542, 2642, 2742, 2842, 2942, 3042, 3142, 3242,  3422, 3423, 3424, 3425, 3426, 3427, 3428, 3429, 3442, 3542, 3642, 3742, 3842, 3942, 4042, 4142, 4200, 4201, 4202, 4203, 4204, 4205, 4206, 4207, 4208, 4209, 4210, 4211, 4212, 4213, 4214, 4215, 4216, 4217, 4218, 4219, 4220, 4221, 4222, 4223, 4224, 4225, 4226, 4227, 4228, 4229, 4230, 4231, 4232, 4233, 4234, 4235, 4236, 4237, 4238, 4239, 4240, 4241, 4242, 4243, 4244, 4245, 4246, 4247, 4248, 4249, 4250, 4251, 4252, 4253, 4254, 4255, 4256, 4257, 4258, 4259, 4260, 4261, 4262, 4263, 4264, 4265, 4266, 4267, 4268, 4269, 4270, 4271, 4272, 4273, 4274, 4275, 4276, 4277, 4278, 4279, 4280, 4281, 4282, 4283, 4284, 4285, 4286, 4287, 4288, 4289, 4290, 4291, 4292, 4293, 4294, 4295, 4296, 4297, 4298, 4299, 5042, 5142, 5242, 5342, 5420, 5421, 5422, 5423, 5424, 5425, 5426, 5427, 5428, 5429, 5442, 5542, 5642, 5742, 5842, 5942, 6042, 6142, 6242, 6342, 6420, 6421, 6422, 6423, 6424, 6425, 6426, 6427, 6428, 6429, 6442, 6542, 6642, 6742, 6842, 6942, 7042, 7142, 7242, 7342, 7420, 7421, 7422, 7423, 7424, 7425, 7426, 7427, 7428, 7429, 7442, 7542, 7642, 7742, 7842, 7942, 8042, 8142, 8242, 8342, 8420, 8421, 8422, 8423, 8424, 8425, 8426, 8427, 8428, 8429, 8442, 8542, 8642, 8742, 8842, 8942, 9042, 9142, 9242, 9342, 9420, 9421, 9422, 9423, 9424, 9425, 9426, 9427, 9428, 9429, 9442, 9542, 9642, 9742, 9842, 9942.

Ответ: 281 раз