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Count the seats
Find the rule before calculating the number of seats.
Identical square tables are pushed together in a straight row for a party. One table seats 6 people. Two tables joined seat 10 people. Three tables joined seat 14 people. The pattern goes on in the same way. How many people can sit at 20 joined tables?
Show the step-by-step solution
- figure 1 = 6 chairs
- figure 2 = 10 chairs
- figure 3 = 14 chairs
- difference = 10 - 6 = 4
- difference = 14 - 10 = 4
- the count goes up by 4 each time
- from 1 table to 20 tables there are 20 - 1 = 19 gaps
- figure 20 = 6 + 19 × 4 = 6 + 76 = 82
Ans: 82