How many distinguishable ways are there to write 9 as the sum of 1's, 3's and 4's, where the order of the addends matters? For example, 1 + 3 + 4 + 1 and 4 + 1 + 3 + 1 are two different ways.
1134 1143 1224 1233 1242 1314 1323 1332 1341 1413 1422 1431 2124 2133 2142 2214 2223 2232 2241 2313 2322 2331 2412 2421 3114 3123 3132 3141 3213 3222 3231 3312 3321 3411 4113 4122 4131 4212 4221 4311 Total = 40 such numbers
Sorry, I thought 2 was included!!
1134 1143 1314 1341 1413 1431 3114 3141 3411 4113 4131 4311 Total = 12 ways
