Rahul simplified an expression. His work is shown below. 7 (8.5 minus 1.5) + 8 divided by 2
Step 1
7 (7) + 8 divided by 2
Step 2
49 + 8 divided by 2
Step 3
57 divided by 2
Step 4
28.5

Where did Rahul make his first mistake?

An automated water dispenser fills packets with one liter of water on average, with a standard deviation of 5 milliliter. the manual says that after a year of operation the dispenser should be tested to see if it needs recalibration. a year later a number of filled packets are set aside and measured separately. it is found that the average packet now contains about 0.995 liters. does the dispenser need calibration? explain your answer.

The base of a triangle exceeds the height by 7 centimeters. if the area is 400 square centimeters, find the length of the base and the height of the triangle.

Geometry in the diagram, ∠abc is a right angle. ∠dbc = 30°27'40". find the measure of ∠abd.