An electric kettle has two heating coils. when one coil is used, water in the kettle boils in 5 minutes, while when second coil is used, same water boils in 10 minutes. If the two coils, connected in parallel are used simultaneously.the same water will boil in time
A. 9 min 20 sec
B. 5 min
C. 7 min 30 sec
D. 2 min 30 sec