The num of ways in which four letters can be selected from the word 'DEGREE', is

Step-by-step solution

There are 6 letters in the word 'DEGREE', namely 3E's and D, G, R. Four letters out of six can be selected in the following ways: (i) 3 like letters and 1 different, viz. EEE + D, G, R (ii) 2 like letters and 2 different, viz. EEE + any two of D, G, R (iii) All different letters, viz. EDGR So, the total number of ways = ^3 C₁+ ^3 C₂+1=3+3+1=7