zhaoyp

It is -15.

In the first formula, think of expense and cost as negative numbers, etc.

Econ pension exp = -Current service cost - interest cost + actual investment return
Econ pension exp = - 63 -29 + 77 = -15

Your pension will cost you the Current service cost, payment for interest, then you get back as an adjustment actual investment return. Always think whether you are paying money or getting money.