Consider the expression.7n‌‌=(1+6)n ‌‌=‌nC0+‌nC161+‌nC262+‌nC363+...+‌nCn6n ‌‌=1+6n+62[‌nC2+‌nC36+...+‌nCn6n−2] ‌‌=1+6n+36λ Therefore, 7n−6n‌‌=36λ+1 7n−6n−50‌‌=36λ−49 7n−6n−50‌‌=36(λ−2)+23 7n−6n−50‌‌=36µ+23 Therefore, the remainder is equal to 23 .