Question

The shaded boxes in the figures below represent a sequence. If figure 1 represents the first term and this pattern continues, how many shaded blocks will be in figure 35?​

Answer 1

The number of shaded boxes in the 35th figure would be 148

The first to third term are :

• 12 , 16, 20

The nth term of a sequence is defined by the relation :

• 
  `a_(n) = a + (n - 1)d`

common difference, d = 16 - 12 = 4

Now we have ;

`a_(35) = 12 + (35 - 1)4`

`a_(35) = 12 + (34)4`

`a_(35) = 12 + 136`

`a_(35) = 148`

The number of shaded boxes in the 35th figure would be 148