You have to find out what 15% of $78 dollars is. If you have to do this in your head and not on a calculator you can find 10%, then cut that number in 1/2 and add it to the answer. So 10% of $78 is 7.8 so $7.80. You can divide 7.80 by 2 and get 3.9 and add that to 7.8 which is 11.70. So 15% of $78 is $11.70.
3,000,000,000,000+600,000,000+30,000,000+200,000+90,000+50+8
14+36+h=400
50+h=400
-50 -50
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h=350mm
This is the answer if your question
