A null remote procedure call (RPC) (carrying 0 data bytes) takes 1.0 msec, with an additional 1.5 msec for every 1K of data carried. How long does it take to read 32K from a file server, issued as 32 separate 1K RPCs?

Explanation

Each 1K-payload RPC costs the fixed null-call overhead of 1.0 msec plus the 1.5 msec charged for its 1K of data, i.e. 1.0 + 1.5 = 2.5 msec per call. Reading 32K as 32 separate 1K RPCs therefore costs 32 × 2.5 = 80 msec in total, option (ii). The 48/49 msec options incorrectly apply the per-1K data cost only once across the whole 32K instead of once per call, and 100 msec overstates the true per-call cost.