1-b 2-c 3-(3) 5-d 6-a

(Q10) Sara, Kyna, Riddhi can complete the work W1, W2, W3 alone in 6, 9 and 15 days respectively. If (Kyna, Riddhi), (Riddhi, Sara) and (Sara, Kyna) can do the work W1, W2, W3 respectively in n days each, then n lies in
(1) (3, 3.5)
(2) (3.5, 4)
(3) (4, 4.5)
(4) (4.5, 5)
(5) either none or atleast 2 of these