Mr. and Mrs. Seventh have 7 children, all born on April 1st, actually over six consecutive April 10ths. This year, for their birthdays, Mrs. Seventh made a cake with candles for each one - the number of candles equal to the number of years of each one. João Seventh, the son who loves Math the most, noticed that this year the total number of candles is double what there was 2 years ago and that there are 2 more cakes. How many candles will be lit this year?
The births occurred on six 1st of April, so there are twin siblings. Since this year we have 2 more cakes than 2 years ago, it means that 2 years ago the youngest had not been born yet, the second youngest had just been born, and the twins had already been born. Currently, the youngest is 1 year old and the twins are $x$ years old with $x \geq 3$. We have:

$$
\underbrace{1+2+3+4+5+6+x}_{\text{number of candles this year}}=2 \times \underbrace{(1+2+3+4+x-2)}_{\text{number of candles 2 years ago}} \Rightarrow x=5
$$

Therefore, there will be $1+2+3+4+2 \times 5+6=26$ candles lit.