+0

# Use the formula to find the 19 square number.

0
427
1
+225
• The formula for the nth square number is Sn =n2.

Use the formula to find the 19 square number.

The 19 square number is =

• It takes you 51 seconds to walk from the first  (ground) floor of a building to the third floor. How long will it take you to walk from the first floor to the sixth floor  (at the same pace, assuming all floors have the same height)?

It will take seconds to walk from the first floor to the sixth floor.

• Cindy was asked by her teacher to subtract 3 from a certain number and then divide the result by 9. Instead, she subtracted 9 and then divided the result by 3, giving an answer of 40. What would her answer have been if she had worked the problem correctly?

The answer would be if she had worked the problem correctly.

Sep 6, 2017

#1
+100540
+2

19^2   =  361

Each floor  takes  [ 51] / [ 3 - 1]  =   51/2  =  25.5  seconds

So....... from the first to the sixth - 5 floors -  takes     5 * 25.5  = 127.5 seconds

Cindy was asked by her teacher to subtract 3 from a certain number and then divide the result by 9. Instead, she subtracted 9 and then divided the result by 3, giving an answer of 40. What would her answer have been if she had worked the problem correctly?

[ N - 9] / 3  =  40   multiply both sides by 3

N - 9  =  120       add 9 to both sides

N  = 129

So....the correct answer should be

[ 129 - 3 ] / 9  =   126 / 9  =   14

Sep 6, 2017