The answer is
3 + (2) (4) - 4
answer is 7
<span>Isaiah puts a 10 gram weight on a pan balance. To balance the scale, he needs to put 10 pieces of 1 gram weights which will be equivalent to 10 grams of weight. Hope this answers the question. Have a nice day.</span>
Since they are similar both dimensions would have the same ratio. The ratio of 5 and 15 is 3. 15 is 3 times larger than 5, so the unknown dimension is 3 times larger than the known dimension.
3 x 10 = 30
The unknown dimension is 30