Unit price elasticity decrease in total recenue

CFA Level I Economics
#1

Price elasticity of a linear demand curve is -1 at the current price, an increase in price will lead to

  1. No change in total revenue

  2. Decrease in total revenenue

I picked no change in total revenue, but the answer is decrease.

i thought at elasticity less than -1, that is -1.5 or -2, total revenue will decrease but at unit elasticity, total revenue will remain unchanged.

#2

At the point of unitary elasticity, total revenue is maximized; any movement away from that point reduces total revenue. (Technically, it could result in no change in revenue – if the demand curve were an hyperbola whose equation is PQ = k, a constant – but we usually assume that there is a single point of unitary elasticity, not a range.)