Question 128957
T=THIRTY SEC COMM.
S=SIXTY SEC COMM. 
T+S=12 OR T=12-S
.5T+1S=10
.5(12-S)+S=10
6-.5S+S=10
.5S=10-6
.5S=4
S=4/.5
S=8 SIXTY SEC COMM ARE USED.
T=12-8
T=4 THIRTY SEC COMM ARE USED.
.5*4+1*8=10
2+8=10
10=10