1}ken spent $720 to buy a total of 12CDs and VCDs.If the prices of each CD and each VCD are $80 and $50 respectively,how many CDsand VCDs did ken buy?
2}there are 950 students in a secondary school.if the number of boys is 32more than that of the girls,how many boys and girls are there in the school?
PS.i need steps !!!THANK YOU
更新1:
the value of two digit number is3 times the sum of the two digit.if 9 is added to this two digit number,the new value will be 4 times the sum of the two digit.find the two digit number PS.i need steps !!!THANK YOU