Explanation

Let the number be x

Then,

⇔34x−13x=60

⇔5x12=60

⇔x=(60×125

)⇔x= 144

Explanation

If 80 people complete the bridge in 20 days, then the total man-days required to complete the bridge is 80 people * 20 days = 1600 man-days.

Rounding up to the nearest whole number, 70 people will take approximately 23 days to complete the bridge

Explanation

• The odd one out is: 54
• The other numbers in the list (10, 25, 45, 75) all end in 5, while 54 ends in 4.

Explanation

Accepted proposal: rejected proposal

75%:25%

75/25:25/25

3:1

Explanation

If they sold 25% of the lights, they have 75% of the lights left. We are given that 75% of the lights is 1500:

$$0.75x=1500$$

Solve for $x$:

x=1500/0.75

​=2000

So, the total number of lights initially was 2000.

Explanation

Pythagoras is considered the founder of the basic laws of geometry.

His work, particularly the Pythagorean theorem.

This laid foundational principles for the study of geometry.

Explanation

ND-6-09-2023

Explanation

Total students = 27

Since 7 more girls than boys, let's represent the number of boys as x.

Number of girls = x + 7

Total students = Boys + Girls

27 = x + (x + 7)

Combine like terms:

27 = 2x + 7

Subtract 7:

20 = 2x

Divide by 2:

10 = x

Number of boys = 10

Number of girls = 10 + 7 = 17

Therefore:

Total girls in the class = 17

Explanation

Average weight of 16 boys = (50.25 × 16 + 45.15 × 8) / 16 + 8

= 804 + 361.20 / 24

= 1165.20 / 24

= 48.55 kg.

Explanation

2:7 :: X:49

7*X = 2*49

7X=98

x=98/7

X=14