1. In a rare coin collection, there is one gold coin for every three non-gold coins. 10 more gold coins are added to the collection and the ratio of gold coins to non-gold coins would be 1:2. Based on the information, the total number of coins in the collection now becomes
(a)90 (b)80 (c)60 (d)50
Initial ratio = G:N = 1:3 ---(1)
After adding 10 gold coins, the ratio becomes (10+G):N = 1:2 ---(2)
On solving (1) & (2), we get, G=20 and N=60.
Presently, the total number of coins in the collection = (10+G)+N= 10+20+60=90
2. A gardener has 1000 plants. He wants to plant them in such a way that the number of rows and the number of columns remains the same. What is the minimum number of plants that he needs more for this purpose?
(a)90 (b)24 (c)32 (d)34
If the number of rows and number of columns are to be equal, then the total number of trees will be in the form of x2, which is nothing but a perfect square. As 1000 is not a perfect square, we need to check for a perfect square above and nearest to 1000.
It’s 1024, which is square of 32. So he needs to add 24 more trees to get 1024.