Nick's cell phone was initially empty but was then charged for 45 minutes and has reached a 25% charge. How much longer must the cell phone be charged to reach 100% charge?
Let's think: The ratio between the time charged and the time to be charged is 100 / 25 = 4. To reach 100%, the cell must be charged for 45 minutes * 4 = 180 minutes. Subtracting the 45 minutes that Jimmy already used to charge the cell phone, there are still 180 - 45 = 135 minutes of charging time left.. The answer is: 135.

Erwan went on shopping. He purchased a pair of shoes at $200 but discounted 30%, and two shirts at $80 each. Upon checkout, the cashier said that there is an additional 5% discount. How much did he spend after all the discounts?
Let's think: The total discount of a pair of shoes is $200 x 30 / 100 = $60. He spent $200 - $60 = $140 for a pair of shoes. The total cost of two shirts is $80 x 2 = $160. The initial cost of his purchase is $140 + $160 = $300. He got an additional $300 x 5 / 100 = $15 discount upon checkout. Therefore, Erwan spent $300 - 15 = $285 after all the discounts.. The answer is: 285.

Phyllis has two gardens. In the first garden, she has 20 plants and 10% are tomato plants. In the second garden, she has 15 plants and 1/3 of these plants are tomato plants. What percentage of all the plants in her two gardens are tomato plants?
Let's think: The first garden has 2 tomato plants because 20 x .1 = 2. The second garden has 5 tomato plants because 15 x (1 / 3) = 5. She has 7 tomato plants in total because 2 + 5 = 7. She has 35 plants in total because 20 + 15 = 35. The proportion of tomato plants is .2 because 7 / 35 = .2. The percentage of tomato plants is 20 because .2 x 100 = 20.. The answer is: 20.

At the circus, the clown has 3 dozen balloons on a string in his hand. 3 boys and 12 girls buy a balloon each. How many balloons is the clown still holding?
Let's think:
The clown is holding 3 x 12 = 36 balloons. This many children buy a balloon: 3 + 12 = 15 kids. After the children buy the balloons, the clown is holding this many in his hand 36 - 15 = 21 balloons.. The answer is: 21.