Explanation

- Start time: 08:50

- Registration: 10 minutes → 08:50 + 10 min = 09:00

- 3 lessons × 55 minutes = 165 minutes → 09:00 + 165 min = 11:45

- Break: 15 minutes → 11:45 + 15 min = 12:00

- Lunch: 1 hour → 12:00 + 1 hour = 13:00

Explanation

Let total salary = S

1. Spends 1/3 on personal affairs → Remaining = (2/3)S  

2. Gives half of remaining to wife → Remaining after this = (1/2) × (2/3)S = (1/3)S  

3. Invests 75% of final remaining → Invested = 75% of (1/3)S = (3/4) × (1/3)S = (1/4)S  

   So final amount left after investing = Remaining - Invested = (1/3)S - (1/4)S = (4/12 - 3/12)S = (1/12)S

Given this final amount = 1000  

So, (1/12)S = 1000  

=> S = 1000 × 12 = 12,000

Explanation

Casey can carry 4 boxes per trip.

Total boxes = 33

Number of trips = 33 ÷ 4 = 8.25

Since he can’t make a fraction of a trip, he needs 9 trips.

Explanation

o find average speed:

Speed = Distance ÷ Time

Distance = 7 miles  

Time = 40 minutes = 40 ÷ 60 = 2/3 hours

Speed = 7 ÷ (2/3) = 7 × (3/2) = 10.5 mph

Explanation

Since the expression includes multiplication by zero (6 × 4 × 0 × 100 × 0.34), the entire product is zero.

Explanation

- Speed for first half = 1 km/hr  

- Time for first half = 2 hours 30 minutes = 2.5 hours  

- Distance for first half = Speed × Time = 1 × 2.5 = 2.5 km  

Total distance between towns = 2 × 2.5 = 5 km

- New speed for second half = 1 + 2 = 3 km/hr  

- Time for second half = Distance ÷ Speed = 2.5 ÷ 3 ≈ 0.833 hours = 50 minutes (approx)

Explanation

To find the average:

(25 + 20 + 17 + 19) ÷ 4  

= 81 ÷ 4  

= 20.25

Explanation

Given that x added to itself 13 times gives 112:

x + 13x = 112

14x = 112

x = 112 / 14

x = 8

Explanation

x = average of k and 15 = (k + 15) / 2  

y = average of k and 5 = (k + 5) / 2  

Average of x and y = (x + y) / 2  

= [ (k + 15)/2 + (k + 5)/2 ] / 2  

= [ (k + 15 + k + 5) / 2 ] / 2  

= (2k + 20) / 4  

= (k + 10) / 2  

Explanation

Only one pair (Red + Blue) is less than 70, so the statement "any two of them together weigh at least 70 pounds" is not true for all combinations.

Correct answer should be: b. no