Question

minimum no. of capacitor of 2uf each required to obtain a capacitance of 5uf

Answer 1

min 4 capacitor is required

Answer 2

According to question

Let the Number of Capacitors needed be n

Each Capacitor = 2 micro f
Total Capacitance = 5 micro f

In series connection

1/C = n/c
  1 / 5 = n / 2
Thus     n = 2/5 = 0.4

In parallel connections
nc = C
 n = 5/2 = 2.5

Thus minimum 3 capacitors are needed