SAT数学题AmerchantsellsthreetypesofclocksChimesntimeonthenthhour|Chimesonceonthehour|ChimesonceonthehalfhourTypeA1010TypeB5TypeC33（是个表格,三列数对应上面的三栏,空的的就表示没有）Amerchant

Question

SAT数学题 A merchant sells three types of clocks
Chimes n time on the nth hour|Chimes once on the hour|Chimes once on the half hour
Type A 10 10
Type B 5
Type C 3 3
（是个表格,三列数对应上面的三栏,空的的就表示没有）
A merchant sells three types of colcks that chime as indicated by the check marks in the table above.What is the total number of chimes of the inventory of clocks in the 90-minutes period from 7:15 to 8:45?
答案为什么是149?

Answer 1

15*8+3+13*2=149