gmat数学题。if n is a positive integer and n^2 is div

1. gmat数学题。if n is a positive integer and n^2 is div

72=8*9=2*2*2*3*3
          若72a=2*2*2*3*3a=n^2
所以n最小为2*2*3=12，a=2。

2. GMAT数学if 10^50-74 is written as an integein base10 notation。。。？

integein
写错了是integer
in.
假如10^50-74写作一个十进制的整数，那么这个整数的各个数字的总和是多少？
10^3
=
1000
-
74
=
926
10^4
=
10000-74
=
9926
10^5
=
100000
-
74
=
99926
规律：50-2=48个9和26
所以：
48*9+2+6
=
432
+
2
+
6
=
440
C