Function ? represents either addition or subtraction, what is the value of 3?4?

1)      (3 ? 0) ? 4) = (3 ? (4 ? 0)

2)      这个肯定可以

X+Y=Z?

1)      X+Z = Y

2)      Y+Z = X

Gross profit was 15% of cost and cost is $200, increased profit by $20, what percent is the profit to cost now?

19%

21%

23%(my choice)

25%

27%

Isosceles triangle ABC, angle ABC = 70’ which angle below can be angle ACB

1)      40’

2)      55’

3)      70’

我选1，2，& 3

(4)⁶(3)⁵ + (16)³(3)⁵ = ?

Ans: (2)¹³(3)⁵