Henry had 20 convertibles and 5 trucks in his miniature car collection.after henry's aunt bought him some more miniature trucks,henry found that one-fifth of his collection consisted of convertibles .how many trucks did his aunt buy?

75

Step-by-step explanation:

Henry started with 20 convertibles and 5 trucks.

His aunt bought him x miniature trucks.

Now, his convertibles represent 1/5 of his collection.  How many trucks did her aunt buy?

So, if his convertible represent 1/5 of his collection now, that means his collection is 5 times larger than the number of convertibles.  We know he has 20 convertibles... so the collection now counts 100 (5 * 20) items.

Out of 100 items, we remove the 20 convertibles to get a total of 80 trucks.

Then we subtract the initial 5 trucks... so, his aunt bought him 75 trucks.