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Current time:0:00Total duration:3:14

Video transcript

a pair of jeans that regularly costs $40 is on sale for 30% off as part of a promotion each customer will also receive an additional discount on the marked sale price at the cash register if the final price of the jeans was $22.40 what additional discount was applied to the marked sale price all right this is interesting and useful because we need to know what we're gonna pay for our jeans alright so the regular price is $40 we're gonna assume everything is in dollars so in sale for 30% off well if your 30% off that means it's going to be it's gonna cost 70 percent of the regular price so let's put 70 percent of 40 so let's multiply that times 0.7 which the same thing as 70 percent zero forty times 0.7 that's going to be equal to twenty eight twenty eight dollars right yeah 7 times 4 is 28 point seven times 40 is also going to be 28 all right so it's going to be 28 dollars would just be the 30 percent off but the final price of jeans was 20 to 40 what additional discount was applied to the marked sale price well to figure that out we can just divide we could say well what fraction of 28 is 20 to 40 20 to 40 divided by divided by 28 well this is going to be equal to let's see 28 and actually you could even you could even rule out well I'll do the arithmetic right over here so 28 goes into 22 20 to 40 so get the decimal right over here 28 doesn't go into 22 but it does go into 224 let's think about it how many times does 28 go into 224 I don't know maybe maybe 7 times let's see if this works so it goes 7 times 7 times 8 is 56 7 times 2 is 14 plus 5 is 19 and then if we were to subtract let's see we could make this a 14 regroup from here this would be a 1 but then we regroup from here this would eleven 14 minus 6 is 14 minus 6 is 8 11 minus 9 is 2 ok so we actually could have gotten one more in there so let's see this is going to go 28 goes into goes into 2 24 exactly 8 times 8 times 8 times 8 is 64 64 8 times 2 is 16 plus 6 is 22 no remainder so this is this is 80% of the marked down price so if this is 80% if this is 80% of this then the then the additional discount that was taken is going to be 20% because you take once you take 30% off you would expect to pay $28 but you only paid 80% of that so they took off another 20% they took off another 20% if you take off 20% then you're going to pay 80% of the price